xkcd

These are very broad statements that are not very easy to comment on. "Every single idea", makes it sound like they are a lot, I would not say they are. "Was rejected", depends what you mean... " did not show positiv results", "no longer possible to motivate economically", sure, " refuted as bullshit", not so much. "Was made more complex", sounds like there is intent, and/or, depending on what you mean by complex, that it would be necessarily a bad thing to using more advanced maths to formulate things you could not before, and hence solve new problems.

I can mention two possible avenues of inquiry that are less than 5 years old that has sprung from string theory as possible support for it: signals of black hole structure in gravitational wave 'ring downs' of black hole mergers, and the exclusion of a positive cosmological constant. But if you know that these are untestable or rejected, I'd love to hear about it.