The problem is, it's much easier to be socially engineered into installing something from the Play Store, or far worse, the Chrome Web Store, and both have extremely unchecked amounts of malware.
The real difference is between "apps that have to give Google 30%, and apps that don't".
I think even when you sum those two quantities it'll still be less than the number of people getting hit by apps from the regular play store.
Likely but not because no filtering at is is better than mediocre filtering rather precisely because it's not easy for a user to "accidentally" side load.
Tons of apps are referencing 100% turing complete web content and not taking flak.
NORPS don't "accidentally" side load by means of typing stuff in a terminal that makes them both feel hackerman and scared shitless at the same time.
Only boomers and ties believe it's not about anti competitive behavior.