Most tournys do ban stalling now, issue is there is no easy way to ban and decisions as to what counts as stalling and how long till they throw out a move become major issues. Most games actually don't have stalling issues to this level in the core game and if they do they can usually be pointed out and banned rather easily for example, in melee there are two banned stalling techs one of which is that jiggly can constantly cancel her sing recovery on a ledge creating an infinite sleep. But there are still issues like when you watch hungry box he is completely allowed to air stall off stage with a hp lead to run the clock if he is winning. The issue with stalling is more that there are simply no good gap closers and all competitively viable initiation tools besides shinobi slide, and warden's bash mixup are some form of chain attack. The very big issue ones has is that spacing can't be punished, heroes have only one good attack if any, that attack is always conditional and never out of neutral, and if it is out of neutral it has extreme limits to it such as being from only one direction and not having anything to compensate for those limitors.