Other languages are able to compile much faster than Rust on the same hardware.

So while adding hardware helps (up to a point), Rust is definitely an outlier when it comes to compilation speed.

This really isn't true compared to C++. Also Rust is doing more than basically every other language, so it's provably slower.

I don't have a good idea about the compilation speeds of C++, so I don't doubt you on that point.

That's hardly the only other AOT language competing with Rust though, and while some of them are simpler on a language level (i.e. C) the compilers do a fair share of work in the optimizing stage of those simpler languages. There's also several languages that do quite a bit of heavy lifting during compilation, like Zig and Nim have extensive compile time features for example. And Nim does two passes since it compiles to C first (by default) and then that's compiled to machine code.

On balance, I don't think you can wriggle out from the fact that Rust compiles slowly compared to its competitors.

Even the Rust team admits this and are working on improving it.

If you want to use rust, and can achieve fast enough performance by simply buying some newfangled threadripper machine with a boat load of ram, what difference does it make?

The OP sounded like they wanted to use rust except for this one issue of compilation being too slow for their development style.

How fast is fast enough and is that achievable just by throwing some money at the machine?

Perfect is the enemy of good enough as they say.