[wh0knows]

This is pure speculation, but is it possible that Android never would have been successful (or as successful) if they did not bow to the carriers? By taking carrier-friendly positions they built a symbiotic relationship that resulted in the carriers being happy to promote their phones.

[JoBrad]

Apple didn’t bow to the carriers. You can speculate that only Apple could have done that, but Google’s deference to carriers has continued with RCS. Given their market position now, I think it’s just a preference in doing business.

[IgorPartola]

The thing is that Android is open source (at least nominally). So having Google refuse carries the ability to customize it would be like having the Linux project say that companies can’t ship their own distros.

Google could have applied pressure on carries via some sort of “Certified Android” label but realistically this is very different from iOS/Apple where the hardware and software are closed and made by the same company.