I can't really speak to the arguments you've presented. Frankly, they seem totally explicable for any number of reasons, but it's not my field. My feeling is simply that tons of people who work in the field believe that HIV causes AIDS (it also totally makes sense to me you could have an immune deficiency without some specific virus, but whatever). So I believe it. If tomorrow, it's discovered not to be the case, I'll probably believe that too. It's not my field, so why would I have a strong opinion? What's the point of even reading a book about it, unless you're working in microbiology?
Science is often said to be self correcting. I no longer believe this. Rather it's ridden with groupthink, politics and power games. I watched in 2020 as the scientific "consensus" about COVID models became defined by whichever factions were most aggressive, most shameless and most willing to lie, despite the evidence right in front of my face. Like I said, I never developed a strong opinion on the "HIV not the cause of AIDS" theory, partly because I don't really care. COVID is far more important. But could scientists end up collectively believing something that just isn't true at all for decades? Yeah, absolutely. I totally believe that's not only possible but quite likely. Scientists will still be claiming that COVID models worked well when we're all in care homes.
As to why anyone should care: because how do you know who to listen to, if you don't evaluate their past reliability? You say that you'll believe anything academics tell you because it's "not your field". Sounds like you might be a scientist? I think a lot of us would like to know what's true even in fields that aren't our own, especially because governments have a habit of making the pronouncements of scientists everyone's problem.
I guess part of my feeling is, sure, science has problems (every scientist will tell you that) but are there better institutions to give us actionable information in the middle of a pandemic? My feeling is no. So, even if I accept your diagnosis of science as "groupthink, politics and power games", I'd say that's just humans. All institutions, all fields are like that. Nonetheless, science has a pretty good record for delivering more or less solid consensus assessments, so even if it does need some reform, I think it's a pretty reasonable bet that the consensus is more or less on the money.
On the topic of consensus specifically, I don't believe that's actually true. Science is full of people claiming there's a consensus but often when investigated it turns out not to be true, and instead there is an ongoing attempt to cover up or suppress disagreement. A claim of scientific consensus always needs to be checked, unfortunately, although that check can often be quite an easy one of the form "does someone make some well functioning technology requiring this belief to be correct".
There is no requirement that information come from institutions, let alone that it be actionable. If you look at where the most accurate information has been coming from throughout it's been bloggers, skeptics, bands of anonymous researchers like DRASTIC and so on. It's not good and it's not better than having trusted institutions, but all such institutions have been hopelessly destroyed from within, largely thanks to ideology. I see no reason to continue genuflecting at their feet of their smoking hulks. Perhaps better institutions will arise, or perhaps people will learn how to filter information and make decisions without being told what to do. Or perhaps both.
We're at a point where scientific work is the sum of an enormous number of specialists, most of whom are only marginally able to judge the work of those outside their field.
That implies that, to engage with a scientific fact (say, global warming) you are always engaging with a gigantic aggregate of facts from an enormous variety of disciplines.
It's just not realistic for a layperson to absorb all the literature that leads to a consensus and come to an informed conclusion. Sometimes, people who are experts in their fields can do something on that level, but ultimately, they're making those summary judgements at the mercy of implicit or explicit consensus, hierarchy, reputation - all the elements of group-think that make up institutions.
I think what you're describing in regards to consensus is just what a consensus is. Take evolution for example: you can't imagine a more starker difference in views between like, Dawkins or Lyn Marguiles over what that word means. So there's a 'consensus', in that both of them are evolutionary biologists, but a dissensus insofar as what they mean by that. People, in a vacuum, have an infinite variety of opinions, many of which are superficially similar, but are different on a ton of subtle points.
There are a lot of problems in this kind of setup, but I feel if you're going to call institutions in western society 'smoking hulks' when it comes to trust or credibility, mainstream science is one of the last ones you should come to.
If I recall correctly, the gist of his argument is like this:
1. When AIDS was new scientists confidently predicted that everyone who caught HIV would die within a year or so. But then people who were HIV+ kept living longer than a year. Rather than treat this as evidence against the link, 'the science' as we call it these days kept being retroactively changed to stretch the supposed incubation period of HIV. This kept going until HIV was claimed to be able to hide non-active for a decade or more.
2. At some point AZT and other anti-retrovirals were developed. These were extremely toxic treatments because they work by stopping cells dividing. They're more like a form of chemotherapy. The drug trials didn't follow the rules of good trials and became hopelessly corrupted, e.g. patients were able to unblind themselves as to whether they were in the placebo group or not and then started trading with others who weren't. They had been told they were guaranteed to die without treatment, so obviously everyone in the process was highly incentivized to get their hands on this supposed miracle drug via fair means or foul. There were many other problems with the trials but that's the one I remember.
3. Not surprisingly given the nature of AZT, people put on it frequently ended up dead even though they hadn't previously been sick. This was interpreted as a failure of the treatment to treat the finally appearing AIDS, rather than the treatment itself killing the patient. The picture was muddied by admissions that of course this therapy had extreme side effects, but it was justified by the guarantee of death that came with HIV.
4. Nonetheless, they kept decreasing the dosages and mixing it with other drugs to reduce the toxicity of the treatments. This was then written up as improvements in the treatment. Duisberg argues they merely kept making a treatment known to be toxic less so. Because (in his theory) HIV wasn't killing the people in the first place, this then led to improving life outcomes which were interpreted as a success for medicine.
5. At this point the HIV/AIDS theory became unfalsifiable. Because HIV was claimed to be a special virus that might kill you very quickly, or might wait decades to do so, everyone with it was given treatment. If they survived a long time, the treatment was the cause. If they died, HIV was the cause. Regardless of what happened the data was interpreted in such a way as to reinforce the theory. Any evidence that disagreed with it was swept under the carpet or fixed via redefinitions, like the addition of HIV positivity to the required symptoms list for AIDS that I previously mentioned.
If you'd like more background then this article by a former science journalist who worked at the Sunday Times might be interesting. At first he believed what he was being told about AIDS, but eventually decided he was being misled and came to feel guilty about his role in promoting AIDS hysteria. He wrote about his experiences here:
https://dailysceptic.org/immunity-hysteria/
https://dailysceptic.org/new-variant/