Interesting when coupled with how many we are losing. It wasn't that long ago that PA-RISC, Sparc, Alpha, Power, MIPS, etc all credibly competed with one another and Intel. Now it's almost all x86-64 and ARM.
ISAs are consolidating sure, but the interesting parts of the chips are also consolidating. A few years ago several companies were designing new Arm cores; now it's pretty much just Arm and Apple.
There are still other companies doing new core designs: Huawei/HiSilicon (Taishan v110 in 2019), Marvell/Cavium (Thunder X2 in 2018), Samsung (M4 in 2019), Fujitsu (A64FX is 2019), Nvidia (carmel in 2018).
If you count semi-custom cores derived from ARM designs, then add Ampere Computing and Qualcomm as well.
