Why is that on Apple instead of the hundreds of other manufacturers and Google? If Google wants a better ecosystem, it’s on them since according to them Android was suppose to be the “definition of open”.
Because while Android is "open", Google has no carrot (Verizon can't charge for OTT messaging and has no major incentive to push it), and no stick (pushing too hard will draw regulators' attention again)
RCS has been stuck in limbo-hell for several years, and I expect it to stay that way (to your point, I expect it to stay that way even if Apple chips in)