Which is also nonfunctional, useless, not for human consumption. You can't filter those in any way. It looks like a relic from the 90s :DDD. Anything else you want to add?
You can easily filter it, by unsubscribing to content you don't actually want. If you watch so little content of a channel that it annoys you to see it on the subscriptions pages, then you shouldn't be subscribed to them.
I can't see how adding a filter system would be less annoying at that point, you would take more time by selecting some filter than just ignoring that specific content. Out of my 352 subscriptions, I got 22 videos yesterday, quite fast to skip them.