> Personally I don't see the benefit of this since you're going to have to recompile your software anyway

The benefit is a unified toolchain. Make a chip, get the entire software toolchain for free.

In the past if you made your own chip you had to write your own assembler, compiler, debugger, etc. Many manufacturers forked gcc but of course it's still a lot of work and the license isn't great (for them, not the user).

This universal compiler toolchain is massive benefit for both the chip makers and the end user.