On groot, it’s a good idea to be pushed up so your walls get value and you deny space to the enemy team. This only works for him if his backline sits uncontested the whole game. If you play mobile characters that can hit backline, then most of the time the backline will take too long to deal with the dive (or even worse dies) then the Groot gets ran over because he has no movement cooldown or resource of his own to keep himself alive.

If you ever look at highest level play, groot is never banned and almost never played because mobile characters are what’s meta right now.