I did a large research about profanity filters in real games once and will reply in very short terms here
Most of simple solutions are very bad (for example, your regular expressions do not cover everything, has lots of false positives, hard to maintain, etc), most of them do not care about tricky obfuscation
There are paid solutions, entire services with advanced profanity filters (according to selected language corpus), then AI that detects hate speech, then, if 2 methods are failing, there is entire squad of real people who are handled those rare unsolved cases manually
It is possible to create such service ourselves, but it requires lots of resources
Considering we have a free-to-play service here, not enterprise one, - development will be very expensive compared to using paid profanity filter service for us
Or not using such filter at all;
Basic profanity filters are trash
Not deery at all