> Like, of course you can prevent all memory safety errors by using a garbage collector. That has been known since the 90s.

No, it's been known since GC was invented.

> In fact, there was a good two decades after Java released where all the research on memory safety just stopped, because the standard answer became "use a GC".

Having done all of my research on memory safety after Java was released, I find this statement a little exaggerated... (e.g., https://barnowl.org/research/pubs/98-pldi-regions.pdf, https://barnowl.org/research/pubs/07-hotos-linux.pdf)

Yeah, my understanding (which is not from first-hand experience) is that a huge part of the origin of Rust was that there was a lot of research in memory safety techniques that had been going mostly unused by mainstream languages, so the idea was "Why not try to make a language using some of it?"