I understand it more as decentralized hosting since it's P2P.
Now, peertube does state something about 'instances', so that might separate content from one accessable website. I don't know.
YouTube's big point initially was video hosting was expensive and YouTube made it cheap (for creators).
It is also is a centralized community so you can find a video on virtually any subject just from the search on the homepage. If peertube is able to do this in a similar fashion would aid it's potential adoption (though again, I don't know if instances hinder that).
PeerTube still needs to be build a user base, attract users and creators from YouTube. Getting creators to use both platforms would help.
Lastly though, since it's P2P I don't know if that means only popular videos would then load at a comparable speed YouTube or not.