That again is why I like the idea of Dooku being a Cassandra.
If the Jedi had listened to him they could have defeated Palpatine but they chose to fight him.
In the current version it wouldn't have mattered which side had won.
Palpatine would win or Sidious would win which sounds kind of fun on paper but ultimately is a bit of a damp squib if you take the saga as a single text, with tragic roads not taken.