I assumed reality would be somewhat less grim as my sample is probably biased towards the ones who complain, but maybe it's so biased that it doesn't even resemble reality at all.
Barely subsisting is definitely not true for a STEM PhD at a decent program though. You're getting paid way less than you could probably, but as long as you're willing to have a couple housemates (usually fellow students) and are not yet supporting anyone else it's a reasonably comfortable wage. Keep in mind that solid health insurance and student perks like university gym membership are also provided at 0 cost.
This might be controversial, but people who have excess expenses (for whatever reason) in their mid 20s probably shouldn't undertake a PhD in the first place. That's the only way a STEM researcher who didn't settle for a subpar school could possibly end up in additional debt as a PhD student IME.
Post doc wages, given the career stage and associated job culture/benefits, are notably shittier. Debt still feels like an exaggeration to me, but a 35 year old with a lot of training and unclear future career prospects should at least be able to support a middle class family lifestyle with their postdoc wages. A 25 year old that is working towards an actual degree and still benefiting from student status is such a different situation.
In hindsight, the maximally enjoyable thing might be to work for FIRE and then pseudo retire to being a PhD student. A PhD can be inherently valuable, the problem is just how tied it is to an insane career path.
Anyway, it's possible the posting students are humanities PhDs? At a good place they still don't pay tuition, but will often get basically 0 stipend. So they legit need loans for living expenses. Either that or Twitter amplifies complaints from schools that one really should not do a PhD at.
The capped length sounds nice, but I think the years they shave off are mostly just at the start, not the years you spend grinding out research. The first year of a US PhD would typically be separated out as an independent Master's degree in Europe.
I have no idea what the academic culture is like over there, so I can't actually say whether it would've been better with regards to the things I disliked about PhD. But the facts you presented don't make me optimistic. A lot of them I don't consider problems in the US personally, and the absolute biggest problem for me is the ridiculous professorship job pipeline.
I'd also be cautious about that 50% US drop out number. It is likely < 20% at a T25 program in any STEM field in the US, certainly in my field that is the case. Perhaps it is higher in CS because people intentionally master out after 2 years to take a lucrative tech job. But I wouldn't consider that failing with the kind of connotation "drop out" has.
I would suggest extra caution before attending a mediocre (or worse) program of course.