We have out and out villains in the saga. Having Dooku right and the council wrong makes him a figure of tragedy therefore infinitely more interesting than just another bad guy with a red stick.
Don’t get me wrong, I am not disagreeing with you on that.
We have many villains in the saga, but only three of them are Sith, rest is just there.
If you were to take out Darth Sidious in episode 1 and 2, you would need to either replace him with someone, or you would need to cut all the related scenes, which would reduce the quality of the movie.(quality is already very very low and many other scenes already need to be cut, you would lose some scenes you can easily salvage if you have a replacement character. If you opt not to replace him and decide to cut him out altogether, you will end up cutting all of the scenes that has Darth Maul in them as a consequence, since most of the time, and in some vital points of the story, they appear together. You would end up with a movie where a sith appears out of nowhere, kills a jedi than just dies. Because most of the backstory scenes has Sidious in them. And after Yoda says there is always two, it would take 2 more movies for the other to appear and it is at the very ending.) Now, you can’t replace him with any other character who is not sith and if you replace him with a new character, whatever character you replace him with has to appear in the other movies for continuity and will need to properly die since that character wont appear in the original trilogy. That would mean editing many scenes along with adding some new scenes, which would be a pain in the ass. (I am probably explaining what I have in mind really poorly, but I hope you understand what I mean)
In my opinion, most of the scenes that features Darth Maul could be quite good, only thing that ruins them is the fact Darth Sidious appears them as well.