Yes, if you assign ‘promote_users’ to another user, that user could promote non-site admins to site admin.
https://codex.wordpress.org/Roles_and_Capabilities#promote_users
Yes, if you assign ‘promote_users’ to another user, that user could promote non-site admins to site admin.
https://codex.wordpress.org/Roles_and_Capabilities#promote_users