Also, searching for your account on any Peertube instance should work fine.
BUT, there's a huge problem. When you have a big creator on the platform, like PewDiePie for example. Every instance would have someone creating a fake PewDiePie. So, either the original creator would go to another platform, or they would need to use bots to create they users on all possible instances. So... creator will not have any incentive on using Peertube, as there's no 100% way to know who's the original.
Remember when Mastodon started, the fake IDs were already a problem: https://mashable.com/2017/04/06/you-cant-delete-your-mastodo...
You shouldn’t need Youtube, Twitter, or some other centralized provider to attest to your identity; you should be able to, with centralized providers only announcing or caching that attestation (just as keybase provided for with proofs). Maybe there’s an easy way to tie this together with FIDO, U2F, etc. I need to do more research.
But I tend to think that a true web of trust model makes the most sense. There may be 250 pewdiepie's on the network, but I'll just follow the one that (1) is closest in my network (followed by my friends) and (2) has the most follows (AKA highest trust).
We already follow this logic of #1 and #2 today even on centralized networks. Web of trust just makes sense to people intuitively.
Who do I know that already knows you? How else can I determine that you're legit? I'm gonna snoop your profile and see what looks legit. Ah, looks like a lot of normal people follow you already.
Of course this isn't full proof. But it's not full proof on centralized networks either. We just need reasonable certainty.
Also, if someone asks me for my YT channel, I just say the channel name and they know where to look, youtube.com.
With peertube you have to: give your channel name, remember then it's NOT youtube, tall then the correct instance, hope they won't type peertube on google and try to search for you in the first instance that comes up.