I don’t think it’ll play out that way. Manufacturers aren’t going to ditch Google. Play Store and Google certification are too valuable for them. And for small developers, most of them rely on Google’s infrastructure. If the EU decides to take that away, only big players with resources could handle their own systems, which ironically makes things less open because indies get squeezed out.
If we skip the Play Services part, the EU might push for sideloading and more openness, but realistically Play Services will remain dominant simply because it’s the easiest and most convenient option for developers. So we’ll probably end up with a halfway solution: technically more open, but practically still dependent on Google.
If we really want change, proper GNU/Linux phones need to catch up or at least run Android apps (APKs) reliably. That alone would solve 70% of the problem. The remaining 30% comes down to infrastructure and right now Google Play Services is just too polished and convenient (especially for indies who don’t care about FOSS ideals) for devs to walk away from.
Yeah but they make their devices terribly slow. I had a 8 y/o Oneplus 5 with Lineage OS 22.2 which was running as fast as my iPhone 13 pro with iOS 26 — which wasn’t the case 3 years back when I bought the iPhone. Unfortunately the motherboard of OP5 is dead because of wear & tear due to everyday use and is not worth the repair cost. So yeah, even my Oneplus 5 got 8 years of software updates (although not officially) and may get some more if the LineageOS team would still maintain it.