The cape gets in the way and can be grabbed to throw or choke you with, the glasses can shatter into your eyes if punched, the shirt ripping is just a more baddass way of taking it off so you dont get blood on it/ lazy way of not needing to draw clothing being destroyed more and more thru-out the battle(just have your mc's muscles flex it out of existence instead!).
Edit: also, removing the glasses is a pyschological barrier being removed since you dont have to worry about having to pay for a replacment and thus can go full out.