But even then larger more complicated apps will get annoyingly slow to “compile”.

It’s when you are working with larger and more complicated Rust or C or whatever code bases that compile time matters.

If you are in the middle of doing a unit of work, iteratively making small changes to the code, compiling, and testing them, those compile times should be small too. If a small change in one file triggers your entire project to recompile, you fucked up the Makefile or structured the whole program poorly or something like that. There’s something wrong that a faster CPU will only mask, not fix.