Why is a "root" MySQL user present in Plesk?

[senthil]

Question
After updating Plesk to 18.0.69 with MariaDB 10.11 and higher, the "root" user is added to MySQL users. Why
is it needed?
Answer
The behavior change was introduced in Plesk 18.0.69
Specifically due to:

• Updating MariaDB to version 10.11 in Plesk on AlmaLinux no longer causes issues with log rotation.
  (PPPM-14895)

The reason behind this is to address an issue with the MariaDB logrotate post-rotation script from the
configuration files provided by MariaDB.