I'd say no, but usually yes. In any competitive environment, usually an entity is incentivized to maximize total value, not value per user. It matters not that

I'd say no, but usually yes. In any competitive environment, usually an entity is incentivized to maximize total value, not value per user. It matters not that a new user is better than the average existing user. It only matters that they are better than nothing. Good things grow, and they get worse per user over time if they can. The book unsong is an interesting read if you find this concept interesting and you like scifi. But there may be some interesting counter examples where group ownership is distributed per user, or with equal voting per user. I imagine in such scenarios, it is possible for quality to increase monotonically. But this would require all existing members to make good decisions about growth - which might not be that easy as it sounds. I wouldn't be able to think of examples off the top of my head... one interesting one to consider might be the group of all humans...