GS-15 is the top of the pay scale though, there's no such thing as a GS-16 just step increases that come with years of employment. Plus, would you really want

GS-15 is the top of the pay scale though, there's no such thing as a GS-16 just step increases that come with years of employment. Plus, would you really want to endure the months of their hiring process (which intentionally filters out people not wanting a long term job) just to join an agency that has no promotion potential for you over the long term?