a lot of us avoid supporting such behavior from corporations because we view it as unethical or immoral and damaging to the sector in general -- regardless of how good the ux/ui may be.
Some of the bad phone UX ideas started on iPhone. Like removing the physical button at the bottom in favor of annoying gestures and no touch ID. And iOS 7 removed all of the borders everywhere, it’s arguably more radical than Google Material, a UI design I also am not really that fond of.
I guess if you mean there’s no A/B testing or it moves slower then probably. But, it definitely moves. That becomes apparent any time you load an app from the App Store that hasn’t been updated in a while and suddenly your phone looks and feels like it did 2 years ago across the whole UI.
And at the very least, these changes come from normal app updates either from the App Store or OS updates. And it's usually a pretty big deal when they change something, and gets a formal announcement months in advance where someone high up gets up in front of the world and pitches why the change is an improvement (not to say it always is). Whereas Google just randomly shunts out new UI updates on a regular basis and enables them for random people. Usually someone posting about their new UI on reddit is the first place you'll hear about the redesigns.
I'm genuinely curious what apps you're talking about here. Everyone does this nonsense. Everything changes all the time. Everything. I don't like it either, but to state that it somehow doesn't happen in the Apple ecosystem seems like a pretty big whopper.
I don't think it was much time later before they moved it to messages.google.com, which i think was in line with their SMS's apps like 5th rebranding, this time from Android Messages to Google Messages.
Originally the app had an overall blue theme, and for individual contacts you could change the color of your conversation with them so each chat thread was themed. This even had the neat effect that it would sync with the web version. However, it only lasted like a week maybe before Google completely redesigned Messages to be all white themed, and killed the chat themes entirely so all message threads were now blue and white to look like the iPhone messages app.
That wasn't a rare experience, and I haven't encountered anything like it since switching to an iPhone.