> Technology can be sandboxed, permissioned, signed, fingerprinted, attested, scanned, and blacklisted.

Many of the things you're listing are the exact things the platforms would have to be banned from doing by the regulation you're proposing because they're the mechanisms used to exclude competitors.

If you put all apps in a sandbox then they can't perform certain operations (e.g. install other apps) which inherently means they can't compete in the market for doing those things. If apps have to be signed by the platform then the signing fee becomes the vig they charge to everyone even if they're using a competing store, and both that and scanning/fingerprinting provide a mechanism to revoke competing apps under arbitrary pretexts and otherwise grief their developers and users.

Attestation is the thing you would have to ban the most because it's not just subject to abuse, its very mechanism of operation is to prevent existing apps that use it from running on a competing new system at the point in time when the new system has too few users for all the apps to explicitly add support for it, thereby preventing the competitor from getting enough users for that to ever happen.

But attestation doesn't prevent grandma from getting scammed anyway. When the scammer calls pretending to be the grandchild who needs money for an emergency, they use the official signed bank app on the attestation-passing device to transfer money to the scammer. When the scammer is using a fake bank app to steal the user's credentials, the fake app doesn't require attestation.

The actual problem here is that you want to have someone vetting apps for grandma, but you don't want the platforms to be able to insist it be them rather than F-Droid or Aurora etc. Which the platforms will try to claim is chicken and egg (how do you know you can trust F-Droid?) while hoping you don't notice that they don't actually get you out of it -- how do you know you can trust Google?

> Many of the things you're listing are the exact things the platforms would have to be banned from doing by the regulation you're proposing because they're the mechanisms used to exclude competitors.

And they should still be banned from forcing apps to do it under their arbitrary judgements in order to participate on their platform. That isn't the same thing as preventing them from doing it. Some people honestly think they love walled gardens (they don't), but some people honestly need walled gardens. There should even be competing walled gardens. Let me install the best kids app store for my kids, and the best grandmas app store for my grandma.

I'm also not sure that attestation should be banned at the app store or platform level; it's a service. I'd ban it at the bank and merchant level. Attestation should be a tool for the user of the device (just like everything else on the phone they own.) They should be able to get it to attest to whatever they want to get it to attest to - if I'm a company and I issue my employees phones, I might want to make sure those phones haven't been tampered with. If I'm a parent and I issue my children phones, I might want to make sure those phones haven't been tampered with. The problem comes when arbitrary people are using it to make sure that the user hasn't tampered with their own phone since it came from some official list of blessed companies.

Let me install the best kids app store for my kids, and the best grandmas app store for my grandma. Let me be able to use attestation to make sure their phones haven't been altered since the last time I checked.

> If apps have to be signed by the platform

I'd like to get back to apps being signed by upstream, so we know they actually come from the author. I couldn't care less if the platform offers a service which verifies those signatures, and if almost everyone uses that service. That's just DNS. If your platforms service becomes hostile, there will be cheap/free competitors, just like DNS.

Just agreeing loudly. But the problem with F-Droid is that it is to be a store that has been blessed by Google in order to avoid legal questions. I know that this is not their fault, and that they hate it. I exclusively use F-Droid and don't even have a Google Play account, but if they started making decisions that I couldn't stand (they haven't, ever) I wouldn't have any alternative.

I remember the bullshit settlement of Microsoft antitrust is that they had to place a modal popup do select a default browser (that I never saw, once, in any context.) No reason why the platform's store can't be demoted to one of a number of stores other than that it is a profit spinner.