well Android Verified Boot also allows changing keys! but like 15 niche phones implement that function out of thousands. out of which it is broken on several such thatit bricks the phone permanently. further, android hardware attestation can make use of AVB, but virtually no apps use it, every app doing such a verification depends on google play integrity, for which you can't change keys and still pass the ckecks.

google has already implemented on android what microsoft is only just dreaming of to pull off, despite preparing it since much earlier. I don't know what they are waiting for, everyone knows there would be no negative consequences to them.