We have RISC-V.

Software binary compatibility is less important now than it has been for 30 or 40 years of x86 dominance because now we are so over-served by hardware that most software runs just fine in emulation (especially transpiling/JIT).

Compatibility also wan't too important in the 70s and the 6502 wasn't compatible with anything else. Everyone expected to rewrite everything back then whether between manufacturers or just a new model from the same manufacturer.