I think you are being a touch dramatic, I am perfectly happy with my google free lineageOS setup. Though I agree with what you are saying and the developing world is not really using LOS I still think there is more hope now than then.
A lot of other apps pops up a dialog saying they need Google services but then work perfectly without it. I'm not a android Dev but it's almost like that behavior is default even if the developer doesn't use any of Google services?
Could the Hooktube Redirector work on mobile too? https://hooktube.com/
On the PC I use that FF extension which sends any Youtube request to Hooktube and works like a charm.
It worked much better for me than the native player and I could download any videos at any time. Definitely a great application.