How much power did the Jedi lose?
In Attack of the Clones Mace Windu notes that the Jedi's ability to use the force has already begun to diminish, logically this also means the Sith's power to use the force has increased. The Junior Novelization even notes in Yoda's duel with Sidious "With the strength of the dark side growing, the Sith must, logically, have grown stronger, too."
How does this impact battle? Would Sidious, for example, be able to defeat Jedi like Mace Windu and Yoda in the High Republic era when the Dark Side did not cloud the Jedi's vision? Did force tilting events like Order 66 heighten Sidious' and Vader's powers?