I think boxing is one of the best self defence martial arts. It's quick powerful and you keep standing on the ground while for example with BJJ you need to get on the ground which is dangerous because you don't know what is happening around you. In a 1v1 BJJ is one of the best martial arts but when there are others involved i don't recommend using BJJ, Wrestling, Judo etc. So in my opinion boxing is the best because you can take on more then 1 person and if you land a blow on his face it's 99 % if the time over. Their are some disadvantages like your knuckles will be broken most of the time so i recommend iron fist training bc your knuckles break easy. The other disadvantage is that blocking punches is really dangerous bc you get hit with knuckles not gloves.