Android

That's because the Linux kernel in Android is very different from the normal Linux kernel. And device manufacturers often only make drivere available for specific Android kernels that are incompatible with normal Linux.

Hallium (I think it's called) makes it possible to use an Android kernel and drivers with normal Linux but that probably comes with its own set of problems. One being that you miss out on newer security patches and features of normal Linux.

It's a mess.

Yeah a really big and fundamental difference between an Android phone and an ARM laptop is that a phone has to have a low level radio stuff that have to be close sourced and fully locked down for regulatory compliance in most countries, so that they transmit radio stuff within legal bands and within legal transmission power and all that, you simply cannot open source those or even keep them user-accesable and mod-able without your device being illegal to be commercially sold as a mobile phone, because then anyone could mod them to operate as radio equipment outside the legal range. And that requires the firmware of those radio stuff to be provided by the manufecturers of those radio chips and devices (not the OEM of the phone).

In fact the inherent complexity and overhead from this was one of the biggest hurdle for early smartphone manufecturers and smartphone OS developers like Nokia and their Symbian OS to become successful. And figuring out how to deal with this efficiently between all of the radio stuff suppliers and smartphone OEMs, was one of the major reasons iPhone and Google's Android were able to succeed commercially in the last decade. In Android this is one of the things that necessitated the HAL or hardware abstraction layer, so that the standardized Android system components and especially Android kernel don't have to directly deal with more than thousands of different models of radio hardware from all kinds of different manufecturers that all require different drivers and such because of how they are close sourced and locked down, whereas on a regular Linux distro running on a normal ARM laptop, the drivers of all those devices can be included into the kernel and redistributed because they are open source.

Any ROM with ships a degoogled version as an option as the changes are in Google Play. So e.g. LineageOS and GrapheneOS are not affected.

I assume any that don't have Google Play Services, which would be those you have mentioned already plus any forks (iodéOS, for example). They would all die if they were made subject to these changes, so the fact that they aren't panicking about it suggests they are safe for now.

I think it will take some adapting of the legislation. IIRC it was a very apple specific decision. Though I don't really know as I'm not European. So take this all with a grain of salt. The fact google is thinking about doing this means they think they will get away with it. They have plenty of lawyers to suss it out for them. Likely they will try to use the fact that they aren't the only manufacturer of android phones etc. Unlike apple and iPhone. Also there technically are alternatives so again not technically a monopoly. All bulshit. But possibly legal bullshit.

The main takeaway is that these companies don't want customers. So we shouldn't give them our business.

Google won't be violating the law, because they are just doing the same thing that Apple does. They do technically allow third party stores, but the devs have to get Google/Apple to sign their keys.

Epic games will be allowed, because they have money to sue. Your average volunteer dev isn't gonna have the money, nor time, to sue.

I think most devs are just gonna publish in F-Droid and let F-droid handle it. F-droid will sign all the apps under their banner, but if Google sees a Youtube alternatibe client in there, I'm guessing they're gonna revoke the signature. And I don't think F-Droid has the money to file a lawsuit. (Do they?)