Well… you can run android without google? The problem is that essential security services require apple or google devices and you as a member of society need the security services.
You can only run LineageOS on smartphones that allow unlocking the bootloader (which is more and more rare), and properly release the kernel source-code (many still don't, especially low-end MTK-based phones...)
Also, how’s isolation on LineageOS for mobile apps? I think I’m getting to the point where I’m thinking of ditching Apple again
I would wholeheartedly recommend going for a Pixel with GrapheneOS. I have been an /e/OS user on a Fairphone for 5 years before reading a lot about GrapheneOS and switching to GrapheneOS. It's honestly so much better!
If you go from iPhone to GrapheneOS, you get better security. If you go from iPhone to anything else, you get worse (to extremely worse) security.
It's also a good proxy for "no results" but then at least you know there is no free app that does what you want just yet :)
Anyway that's what I use to get the proprietary government and other societally required apps, and while I'm not on Lineage right now, it's meant to work there
Maybe a case for the EU? I mean, they like creating laws limiting the power of big tech. Maybe there should be a law that requires all services that are used by public institutions and commercial transaction providers to be transparent to the public and therefore open source. And as a platform provider, they should be required to offer APIs to let users install alternative implementations.
Might require some fine-tuning, but you get the idea.