It's up to him if he wants brain damage I guess, but I don't think it's that amazing to watch.
It's not boring, don't get me wrong, but I mainly like good fights. I'm not watching youtube footage of random people fighting and beating others up. I cringe a little at the amount of punishment he keeps taking almost every fight.
Not saying Gaethje doesn't have skills, just saying he should use them and focus a lot more on defense. This guy might very well end up worse than Goodridge. I hate to see that.