Main issue now is that you are screwed by chance of getting the t-shirt you are looking for.
Reverting to old system where a specific mob drops the shirt you want solved the issue.
Proactive players hunted down the shirt that they were looking for.
Also. there were more mushrooms roaming, but you lost time walking around waiting for re-spawn. Still, the chance to get CHA tshirt on paper was higher.
Annoying to target though. And is the only one I never saw.