“Authentication plugin ‘caching_sha2_password’

So I found the reason for that error message (at least for my case).
It’s because MySQL as of version 8.04 and onwards uses caching_sha2_password as default authentication plugin where previously mysql_native_password has been used.

This obviously causes compatibility issues with older services that expect mysql_native_password authentication.

Solutions:

1. Check for an updated version of the client service you are
   using (most recent workbench for instance).

2. Downgrade the MySQL Server to a version below that change.

3. Change the authentication plugin on a per user basis (I didn’t find a global option, maybe there exists one though).

Now regarding option 3 this is as simple as altering the user:

ALTER USER user
IDENTIFIED WITH mysql_native_password
BY 'pw';

or when creating the user:

CREATE USER 'username'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';

See MySQL Server Blog

See Oracle