Google removed “Ok Google with the screen off” (made the toggle disappear, replaced with the option to allow its use in apps) on my Moto Z Play via Play Services updates and later advertised it as a Pixel-exclusive feature. (this was when the Pixel 1 was new)
Their support threads were ended curtly with statements of the phone not supporting the feature which I guess was technically true now that they changed it. (but no, the hardware always supported hotwords)
Never got that feature back and I bailed. For the ups and downs, I’m glad Apple doesn’t do that, instead omitting or handicapping new features for older devices. Of course not the best but yeesh, at least I don’t have to worry about “Hey Siri” being pulled to promote the iPhone 20 yet…