I see, ok. Yes, UIs can do whatever they want with the posts and can completely ignore the reward pool if they choose to. This is what 3Speak does and what they are advocating for all Hive sites to do. This, though, pretty much removes one of the main points of the reward pool - Proof of Brain. If posts don't gain traction and aren't curated by the POB process, then what is the rewards process for? At that point it will very much just become a system for people to buy stake and then upvote each other - even more than before - since the actual content itself is essentially bypassed in the process of issuing rewards.
Your assessment here is not taking the nuances into consideration. If you didn't already, you can listen to the (heavily downvoted to zero) discussion I had with the 3Speak team on this, here: https://peakd.com/hive-181335/@ura-soul/jgwxmjtg