>If nobody thinks things are worth looking into again then stuff stays in a very nebulous state which is no worse than where things where before a paper was published.

I don't think so, because of the aforementioned idiots who take a study that can't even be replicated but then cite the paper as evidence for something. If it can't be replicated, logic would say there is a very good chance it's inaccurate. Yet it's treated as being "settled science" which is worse.

Also, many times it isn't that nobody thinks it's worth looking into again, it's that coming to "the wrong conclusion" on some things will end their careers so they'd rather play it safe and just keep sucking up grant money to pump out more of the same garbage.

If it’s not worth looking into again then the answer isn’t important. As to what idiots do, they quite literally aren’t worth paying attention to.

Those bad papers are an impediment. It's much harder to get your paper/proposal past reviewers when it's for solving a problem someone else claims to have solved already. Also, even if you do get past that higher barrier at an added expense and time (reviewers will want a lot more evidence to support a claim refuting a prior claim versus a groundbreaking new claim), the person who usually gets cited more, funded more, and a bigger career advantage is still the person who's non-replicable publication was first.