I kinda understand why they do this. Android has slowly been going the route to be only for dummies that shouldn't be able to touch anything. And most device makers are completely fine with it, evidently.
What's needed is a really decent alternative OS, or several, with widespread support across devices.
Yea there's Graphene, but in terms of devices, do you want this year's Google, last year's Google, or an overpriced recycled phone? And in terms of firmware the situation is even more difficult.
Even 10 years later I'm still mad at Firefox for letting go of their FF OS.