Logs that grow in size uncontrollably can cause unintended consequences. If you keep ignoring the situation, it will only get worse until you run our of disc space, the system starts being unresponsive or processes begin to crash.
When updating MariaDB, the popular successor to MySQL, you may, once upon a time, hit a roadblock which you won’t be able to track down in the error log. Even though web visitors get to see the plain text complaint “Can’t connect to the database”, the MariaDB server will be running just fine. Silent errors should be reason enough to suspect SELinux, the oftentimes dreaded and despised but equally popular Security-Enhanced Linux kernel module.