Mace windu was actually strong as fuck though. Like he genuinely bested sidious in saber combat. It wasn’t an act.

The advantage of Vaapad, using Sidious own dark side powers against him.

I read once that obi wan and anakin were so used to sparring together that the difference in power didn’t matter.

It certainly did matter, as seen in their final (RotS) duel; Obi-Wan is on his back foot, running the entire time. It’s true that they had sparred so much, they could predict each other’s movements as if it was telepathy, though.