I think you're wrong about the write-once run-anywhere software ecosystem that Windows had to deal with. There was an incredible proliferation of different hardware -- including drivers etc. -- and it was mostly up to Microsoft to make sure that the OS continued to work flawlessly (or at least at whatever level of semi-stability it managed to attain) across all of these different configurations.

This is an enormous responsibility that Apple has never had to deal with -- there's a difference of at least 3 if not 4-5 orders of magnitude in the number of different types of hardware platforms that each company had to deal with.

Android has a few dozen phones to support. And yes, the "metaphor" is slightly different across phones, but it's nothing like having to deal with every random piece of hardware that every company puts out.