> Obviously, anything with OAuth is "bundled" into my Google account.
Maybe it's just me, but I try to never use centralized identity providers (outside of things that I really don't care about) and use separate e-mail auth whenever possible, across multiple e-mail accounts (some self-hosted). Same with considering separate Google accounts for phones, services like e-mail, a separate one for any content creation on YouTube and so on (ideally without any of them coming in contact with one another).
The idea is that one account getting closed/suspended shouldn't result in ALL of the linked stuff becoming inaccessible. I don't even do anything weird online, it's just that nowadays you hear lots of stories about people getting banned based on some heuristics by automated systems, with no ways of getting in contact with the support. Even something like a VPN might trip those systems up. Similar things have happened to me before (a SaaS provider didn't want to do business with me) for no good reason even without a VPN, but trying a year later with the same credit card didn't result in the other account being auto-suspended. How odd.
I guess the next step would be to have usernames, phone numbers and even payment methods (apparently virtual credit cards sometimes work) also be more randomized and more compartmentalized, though something tells me it'd be a pain to do that. That said, I largely believe that privacy online is mostly dead due to how much fingerprinting there is, though one can still protect themselves from automated systems acting weird, because nobody genuinely cares about that, at least at the scale where they're needed.