It is not an issue for me if trash talk is offensive. It is all about the humour. When Tito, Rampage or Chael used to do it you would be able to laugh. Or they would turn the joke on themselves (not always intentional). This would create memorable moments.
People think he was the best at it but I can’t even recall any trash talk moments from Conor McGregor since the Khabib press conference. I think that is because he just went completely off the rails and ignored his persona had to be somewhat funny at times to work.
Colby basically had a decent gimmick but was too stupid to use it properly. A persona of just being a scumbag is not going to work and I think he will be forgotten pretty fast.