I've saved a good deal of money, and waiting a couple extra days for delivery has only been a minor inconvenience .
I had the same thought a couple weeks ago regarding direct-from-manufactuerer product search / purchase. I'd use it regularly.
I cancelled both Netflix and Amazon Prime last year and decided to do account hopping on a month by month basis. Their greed is what triggered this. Both have gone down a path of less and less interesting content, price increases, and now indeed this ad driven bullshit. I realized I'm paying 20 euros per month for both and struggling to find something worth watching for months.
So, I cancelled both and went over to Apple TV. They don't have a lot but what they have is quite nice. Once I'm done with that, I'll consider what to subscribe to next. Criteria here: whatever I pick has to have stuff I want to watch (ad free, obviously) and I'll unsubscribe the second I get bored. I'm done paying for multiple streaming services at the same time. I only want the good stuff. I'm not interested in the generic filler content, B movies, etc. that are cheap to license but horrible to watch.
I might come back to Netflix or Prime periodically to check certain shows. But not on a permanent basis. If more people do this, that gives them a nice price signal that they need to invest in quality.
It started from using Amazon to research and then looking for alternative larger online stores to buy from when product+shipping more or less matched Amazon.
A couple of times I have found good deals direct from the manufacture that were not available elsewhere, so I make a point of checking there as well now.
It feels like companies are able to setup a competent online store more easily now (billing and logistics).
A competing "direct from the manufacturer" sales site would be useful. Only the business that actually makes the thing could sell it. No intermediaries.