I disagree. Instead of the nebulous, pure evil Sauron that most of the audience already knows, the show has leaned into ideas of Sauron in the 2nd Age that Tolkien had about him, where he is trying to reform himself but also reform Middle Earth in the way he sees fit. His desire for control and power means that his repentance is half-baked, and his seemingly lofty goals for Middle Earth are ultimately perverse, even if he doesn't realize them as such. I think it's great that the show is giving us this Sauron, and also blurring the line between what was perhaps genuine on his part and what were his deceptions and manipulations.
It has accomplished this while playing off the arc of its protagonist Galadriel rather elegantly, full of inversion and counterbalance, the finale really finding a great way to thread that needle of Fate and launch those two characters on really interesting trajectories. It wasn't what I had in mind for this story, but it worked better than I would have thought.
And I know many Tolkien nerds wanted more on this, but the show found a way to quickly and neatly fold in his Lord of Gifts, Celebrimbor influencer, Rings of Power involvement in a way that made sense (while simultaneously finding a good use for the kinda wacky mithril storyline). Could I have watched a season's worth of Annatar in Eregion, sure, but I get why in the show's construct they went this route.
Anyways, just my opinion, sorry the show's take didn't work for you. If you had told me it would be like this a couple months ago, I probably would have been like "oh no, sounds awful." But actually watching how the show set it up and played it out, I am with it.