Youtube, Facebook and company have a ridiculous amount of false positives, for the money (and the people, they have quite a lot of human moderators) they throw at the problem. Also, they enjoy complete market dominance, so even if you want to move out of youtube... where are you going to go?
With the same rate of false positives there will be enough community rage (I guarantee someone is going to find a way to have your system ban the top 10 streamers of your game after 2 days you put it in place) your players (both good and bad) will go somewhere else. :)
The problem youtube, facebook and similar companies face is whole orders of magnitude more complicated than policing a game chat. It is, for example, highly unlikely that you will be censuring honest content when you encounter the words 'gas' and 'jews'.
And even indie companies have to pay the piper when the bad culture and tough decisions that are put off result in blowback.