Why is bull fighting still allowed?

I don’t mind the matadors going around dodging the bulls, but why do they have to stick those swords in their backs and then finally killing them with the last one. :(

I would imagine that that would be unpopular by now. Surely they can show their skills by like doing an assisted cartwheel over the bull or smashing a water balloon full of paint on their backs. I know it’s culture and all but it can totally be made more humane.