Ownership of the .config folder in home directory

Who is supposed to be the owner of the .config directory under user's home folder?

On my machine it appears to be owned by the system user and it is only readable by that user.

Several programs, like Homebrew and git (which should be allowed to be used without root permissions) complain by producing warnings as shown below:

warning: unable to access '/Users/andrea/.config/git/attributes': Permission denied

Perhaps the ownership of my .config folder was changed in mistake? Who should be the owner?

And if system should be the owner, is it safe to make it readable and writable by other users?

The .config folder is supposed to be owned by the user. It appears that the ownership got changed to system by mistake on your machine.

To restore the default permission, execute the following command:

$ sudo chown -R <username> .config

When prompted for a password, enter your login password.

Substitute <username> with your username. To determine your username, execute the following command and observe the output.

$ whoami

Finally, to answer your queries:

Who is supposed to be the owner of the .config directory under user's home folder?

The logged in user is supposed to be the owner of the .config directory.

And if system should be the owner, is it safe to make it readable and writable by other users?

It is not recommended to do that, unless you have some specific reason to do so.