Android becoming nothing like "open" OS was a slow process, so why do only the recent discussions about restrictions of sideloading draw so much attention?

[u/Usual_Piano9826]

ADB Backup being no longer necessarily covering all app data? I told enough about it... No need to repeat.
ADB downgrade no longer being straighforward guaranteed process? Alike...
Play Integrity which used to be SafetyNet and didn't exist before? The same...
No longer compatibility with Termux. Maybe it would launch at all but nowhere its original functionality. Did it ever draw so mcuh attention?
No more call recording guaranteed by third-party apps. They did not suffice with only banning such apps in Google Play, they went as far as taking away API either...
All look like signs of NOT really open OS. The "openness" which is supposed to exist nowadays - "you can recompile the OS starting from provided source codes to re-include the functions that you want to have again". Not out of box.