Why blocking people doesn't prevent them to end up with you in same team again?

Hi guys, So I played LoL and got 3accs permabanned in 2013 for insulting people who were griefing my games by intentional feeding and other behaviours. Now after 7yrs I started playing again and I blocked some troll who was feeding on purpose and insulting too, hoping I won't ever end up in team with him. 2 matches later im in the same team as him -,- .

While my behaviour of insulting people in 2013 was wrong, you as developers are encouraging such behaviour by forcing players to play with people they blocked, also they could dodge in selection but they would end up with penalty for it.

This game is out 11 years and I think preventing blocked people to be in your team should be standard mechanic to make this game more pleasant for everyone, what do you think?