Why arn't any of the people intentionally feeding/giving up getting banned?

I just won a game against 3 players who just walked into us and started dancing, the very first thing they said was "im going to feed", and i keep seeing these players over and over again ruining games. why is this allowed.

I havent had a single game today where my team or the other team hasent had someone just give up and abandon lane and feed, or give up and surrender. What about playing for 20 minutes only to have the first team that looses lane give up and surrender is fun? Why give up just because you didnt happen to get first blood?

Why is surrendering even a option? It just promotes people to feed because they think the game will end faster. This has gotten even worse after they added the 15 minute surrender. Giving up is reportable so why even give players the option to give up?

https://streamable.com/sf8bk it looks like streamable is down