Current behavior:

Currently, Organization Admins, User Access Admins, and team members all share the same permissions: they can invite new members and remove existing ones.

• Reference: Create and manage an Atlassian team

Suggested improvement:

Introduce a Team Admin role.
Only Team Admins should be able to invite new members, and users should be able to join only when invited by a Team Admin.

Team management actions—editing team details, deleting the team, and managing membership—should be restricted to Team Admins, not regular members.