[2019] Why does the report player button exist?

AFAIK when someone is reported in a game their chat log is scanned for certain bannable words like "f*ck" and if they're found the player is banned. Why not just make it an instant mute/ban when a player uses one of these words or even better, censor them? If your answer is context, that wouldn't make sense, since the auto report "feature" takes no context into account.

I just don't get it, if you're with someone toxic or even racist in a game, you'd eventually be driven to reply with one of these bannable words (at least I am) and you'll both be banned; if you were to make it an instant ban/mute/censor, this wouldn't happen, this system just makes no sense.