This will only push Apples stock down. Every big company with market power will move their app off the App Store to stop paying apple a cut and not have to follow their rules (like easy subscription cancelations).
Nah, no chance. Android allows side loading and the vast majority of apps are on the Play Store still because the vast majority of users don’t even know what sideloading is…
No. The EU has published a detailed list of soft barriers to side loading that Google must remove.
It's going to get a lot easier to side load apps on Android soon. And there will probably be a bunch of third party stores (I'd expect Steam to be available on Android this year for example - and probably also pre-installed on some phones).
It’s a ton of work to distribute apps on your own
Sure. But developers don't need to do it on their own. They will be able to outsource the work to someone like Steam who is very very good at running an app store (I'd argue they're better at it than Google or Apple).