> What makes you think they abandon peer review?

Maybe that's because I have much trouble picturing who exactly do you have in mind. I don't know about any major thing solved by unaffiliated scientist. Sure, there are some of the not well regarded discovered some pretty important thing. But they still were operating in the same environment, and once they proven their case sufficiently were embraced by that environment.

> Some of those people do publish peer reviewed papers.

Some? And that's supposed to make them more trustworthy for me than scientists that other scientists trust?

> Unfortunately, peer review is pretty worthless.

As all tools by themselves are. That's why we have the scientific community and that's why you can make a career of mastering all the tools of science. Reputation among colleges has some value as a tool too.

> do you mean Wakefield?

I mean exactly him.

> He was peer reviewed and it took years for his paper to be retracted!

Yes. It takes time. It took even more years of solid journalistic investigation to show how much of a fraud he was. Meanwhile no other better source stepped forward to provide us with better insight on that case. And many "citizen scientists" did their own "research" and found much confirmation for Wakefield claims which they happily pronounced to vulnerable people.

> For COVID stuff, for better or worse the arguments are mostly about data and everyone is working off the same datasets. So you don't need fancy equipment. A computer is sufficient.

Not quite, because data is just the base level, from data you need to extract information, from that knowledge and from that insight. At the level between data and knowledge you need to have a pretty solid understanding of context of given field, like virology or epidemiology or immunology, because without it, from that data, you'll be able to create only mistakes and confusion.

> The man has made an entire career out of being always wrong and nobody in Imperial College London seems to care.

Sure, scientists usually don't spend their careers debunking others that are clearly wrong. They are usually more focused on developing the ideas of the ones who are right, because that's better use of their time. There are ton of garbage science around. That makes me even less confident about things that are not even science.

> The non-affiliated researchers on the other hand are trying to build an audience, some are selling their analysis to readers.

That's a horrible argument. Truth doesn't sell. Lies sell best. Also lies are somewhat resilient and still sell very well in the presence of information debunking them.

> I've seen mistakes caught that way a few times now and it usually leads to a quick admission and apology

I've seen way more doubling down on the lie or mistake than apologies. Apologies usually come from real scientists that have internet thing on the side while having usual fulfilling scientific careers.

> something I never saw coming from academics even in the rare cases their paper was retracted.

That's because retracted papers usually don't come from people who made honest mistake. They come from over liars, who wouldn't apologize or even admit if someone caught their hand while they are stealing. While random person (or non-afiliated scientist) on the internet is more often just misguided and/or incompetent.