> The point of those agreements is to make sure those phone manufacturers didn't basterdize android with their garbage crapware

You're naive if you think these deals were about protecting the user. It's a commercial and strategic play to make sure users end up on Google's core business products.

Manufacturers get a free OS they don't need to develop, Google gets their core business products in every user's hands as default.

They didn't develop an open source browser and OS for any other reason than money.

And they pay (Apple, Mozilla, etc) or commercially force the usage of those products wherever they can.