Which description? That Wikipedia article says "The aim is to provide an alternative to centralized platforms such as YouTube, Vimeo, and Dailymotion."
The difference to YouTube is that it's not intended to create a huge platform centralizing videos from the whole world on a single server farm (which is horribly expensive).
From their website. It's a very different system, and also not funded by advertisers, which means someone else has to pay the bills.
The ambition remains to be a free and decentralized alternative: the goal of an alternative is not to replace, but to propose something else, with different values, in parallel to what already exists.
They're saying they're not a "replacement" because it's a decentralized alternative to something centralized. Not because it can't serve the same needs for technical or economic reasons.
https://en.wikipedia.org/wiki/PeerTube
They explicitly say in their description they're not a replacement for YouTube.
Which description? That Wikipedia article says "The aim is to provide an alternative to centralized platforms such as YouTube, Vimeo, and Dailymotion."
From their website. It's a very different system, and also not funded by advertisers, which means someone else has to pay the bills.
They're saying they're not a "replacement" because it's a decentralized alternative to something centralized. Not because it can't serve the same needs for technical or economic reasons.