The patch set is open source, so is the application that does the patches. I don't feel like it's worse than downloading most apps. Though you still rely on Google services.

not trashing the software itself (haven't tried it), this post and their github repo just felt weird

https://github.com/revanced/revanced-manager for YouTube (and other App mods), you need to patch the app yourself. (If you are downloading a patched apk you are getting scammed. You have to patch it yourself) https://github.com/mihonapp/mihon for manga / manhwa I use internet archives for paywalls but their might be a better solution. F-droid has a a lot of neat open source app, I guess you know of it since you are picking graphene, but just in case. Firefox supports addons, it's been a great browser (though its UI is a bit rough sometimes) and could be your solution for YouTube with uBlock and the background play addons. I personally don't like graphene launcher, I personally use NovaLauncher (the paid version), their is quite a lot of FOSS ones too.

edit: sorry for the formatting, my phone f it up

Is this post using bots for upvotes ?