MySQL service doesn't start in Catalina OSX
After hours investigating I found this post from Michael Fraase: https://discourse.brew.sh/t/mysql-8-0-18-on-catalina-wont-run-as-service/6015/2

I just added:

[mysqld]
user=root


to /etc/my.cnf (or where you have your .cnf file) and it solved it (I can not believe it).