Will once again re-up the concept of a “right to root access”, to prevent big corps from pulling this bs over and over again: https://medhir.com/blog/right-to-root-access
Most of users are not able to keep themselves safe in the internet - they want to install all kind of crap without thinking too much.
All of this is companies making it possible that average Joe could just click links, install any kind of crap and still be somewhat secure.
Right now, the average Joe can't click a link and install a 3rd party app. Meanwhile, you can install malware from the actual authorised sources, or even just come across a vulnerablity in chrome.
Keeping your devices up to date with security patches will save orders of magnitude more people from malicious software than stopping 3rd party app installation.
I occasionally develop Android apps for myself (mostly out of curiosity and experimentation, but sometimes out of a need for some particular functionality). I'm not going to apply for some developer permit and verification just to do this. I may as well buy a damn iPhone.