The problem is the term quality would be used to block out certain creators. The definition would wind up being vague and/or arbitrary.

What one person thinks is quality may not be quality to someone else. In a way that's a niceness of YouTube. We can each upload what we think is good.. or bad.

Even then if a video goes big viral (which is arguably something a creator may want), the bandwidth costs could skyrocket.

Then it's like: maybe we need CDNs and more storage and boom now it's even more expensive. I just don't see fediverse video working great long term without big money to back it.