Well x86 at one point, arm both the 32 and 64 bit versions. I think they had RISCV support in their source tree at one point but not really at a commercial level. It does cover a lot different levels of hardware though

IIRC, Apple uses 'platform' to refer to an SoC integration. For example, M1, M2 and etc. are separate platforms. M5 in Vision Pro is a separate platform than M5 in MacBook Pro. I believe Apple's XNU does somewhat still support non-Apple Silicon as well though.