In order to have an email account you don't go to "email.com", you have to go to an email service provider. Peertube works in the same way so they have a list of providers: https://instances.joinpeertube.org/instances
If you can understand email, you can understand peertube.
So the site is mostly promoting the technology, right? Is there any popular platform that uses PeerTube and actually has interesting or exclusive content?
Peertube = email software
In order to have an email account you don't go to "email.com", you have to go to an email service provider. Peertube works in the same way so they have a list of providers: https://instances.joinpeertube.org/instances
If you can understand email, you can understand peertube.