You can now leave an organization yourself instead of asking the owner to remove you, a useful cleanup if you've accumulated memberships in orgs or workspaces you no longer use.
Non-owners can leave at any time
Owners must transfer ownership to another member first; an organization always needs at least one owner, so the leave action stays unavailable until ownership is transferred
Find it under Settings → Organization → Danger Zone. Leaving removes your access to the organization and every workspace and data set associated with it.
Check out the Organization documentation for full details.