Why does the user Access "All Tickets", control an agents ability to add and edit a customer/user

As the title says, i have just had to raise a ticket due to a test account i was setting up, not having access to create new users/customers (terminology seems to change in different parts of support for the same thing, maybe another feedback comment).   I had set the agents access to "Tickets in agents group, yet have now been told that in order for an agent to add a new user during a new ticket, or to edit users/customers, the access needs to be set to "All Tickets".   Why would the agents access dictate if they can add or edit a user/customer, and what if i dont want an agent to access all tickets, but still want them to add users/customers?

i can see something similar here:-

Agents should be able to create users – Zendesk help

But it only provides what i would call a workaround, but of all the cheek, you need to be on the enterprise plan to do it, and i am on teams.   In addition, the workaround talks about effectively the user assuming the identity of a customer to edit their profile.   An agent should be able to do this without having to assume the identity of the customer, and in the case of a new user, they are not assuming anything, just creating a user. I am also an admin on my admin account, i dont have to assume the customers identity to edit a profile, im just the ADMIN, so i can do it.

Just awful to see the response on the post i linked to.