Why is the disk not mounted under an unprivileged user?

Question

linux

On Ubuntu 20.04, an entry was made in the /etc/fstab file with the option user

/dev/sdb1       /mnt/new_disk   auto    rw,user,auto    0       0

But in fact, the user cannot manually mount the disk

Answer 1

It works!
It just does not allow you to enter two parameters, that is, you need to use
mount / home

Answer 2

because "Only root can do this"

Answer 3

and if this user is added to the disk group?