Do not accept the premise of assholes.
I hope we can get the EU to fund a truly open Android Fork. Maybe under some organisation similar to NL Labs.
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Furthermore, the need for a trustworthy binary to be auditable to a certain hash or something would make banning this a simple task if Google would want to go that route.
This is actually the advantage of doing it. You make the thing (call it a "personal app loader" or something rather than a "circumvention tool"), they ban it, now you campaign against them or make antitrust arguments presenting the ban as an anti-competitive practice or use the ban to refute claims that they're not inhibiting third party app distribution.
Even if you know they're going to be the villains, you still want to make them actually do it so that everyone can see them doing it.
I do think having a technical bypass is good - it isn't mutually exclusive with also having a legal bypass. I just hope that the gov'ts are smart enough, and agile enough, to make this happen before it becomes too late (aka, once the gates close, it will never open again, like apple's ecosystem).