With only two true Sith in existence, it would have made the Jedi even more suspicious of any dark side powers they encountered. Since there were far fewer Sith Lords, if any of their plots were ...
His lack of actual power in the Empire suggests Vader's commitment to the Sith may have been conditional. The ongoing debate about Darth Vader's true Sith status continues to puzzle Star Wars fans.
Thus, the Palapatine/Vader imperial model has no precedential value for any follow-on Sith lord. Each can chart his own path, including by implementing true self-determination to the galaxy.