When a site-admin open other site-admin profile, the buttons for Prompt reset password and Log in as user are disabled and it shows "You do not have enough privileges to prompt this user to reset their password." and "You do not have enough privileges to log in as this user.".
Please, update the documentation explaining what site-admins should expect when they add other users as site-admins and the reason why they can't reset password.

https://confluence.atlassian.com/cloud/give-users-admin-permissions-964957877.html