> we installed stuff on our devices

I am not sure about that. Windows, Linux based devices were like that but for a lot of things like gaming consoles etc. you were locked into the ecosystem and 'side loading" was indeed something.

I do understand developer mindset but I would be pretty unhappy if my mother's phone could just install stuff. A lot of people get harmed and lose their life's saving over wrongly installed crap.

A good middle ground for the Big Tech is to let folks pay $$, a money that is high enough and has sufficient friction.