If you want to protect your privacy against viewers of your videos, how you upload them to YouTube makes more or less no difference. With this scenario the question is how much information are you leaking in your content, and that’d cover everything from writing style idiosyncracies to anything that can be used to potentially identify eg. where you live and so on.

If you’re worried about “malicious hackers”, then the question is who are these potential hackers you’re protecting against? Would they be attacking Google or you? If it’s you, then how you upload things to YT is again completely meaningless. If they’re attacking Google and get far enough to actually exfil data, what they’d actually be able to get out of it is anybody’s guess. Using a VPN and a throwaway email is probably good enough in any case.

Who are you protecting your privacy against here?

Because if it’s Google, then why on earth would you want to upload content to YouTube in the first place?

OK, let’s say you didn’t give them your phone number and masked your voice. If you’re not connecting over a VPN or something like Tor, they still have your IP address.

OK, you now use a VPN, but your browser can still be very effectively fingerprinted and that fingerprint could be nearly unique.

And so on and so on. And this isn’t even going into metadata in & about your video files that could be used to fingerprint the system they were done on.

That has nothing to do with anonymity, though

I don’t quite understand your question. Yes, to share something with someone else, that someone needs to know what you want to share with them and where to get it from – I’m not sure what you envision the alternative is