Nah, the 8th season had its problems but I think a lot of points went over people's head. Understandable as it was rushed.
Tyrion: I'm not particularly good at violence, but I'm good at convincing others to do violence for me.
Dany having Vary's burned alive solidified Tyrion's view on her. He knew that he couldn't reach her. He knew that she had no qualms with killing those who previously helped her. He convinced Jon to do the right thing.
But I think that’s the point. Varys was one of the most intelligent characters in the story. I think the writers didn’t know how to handle him and essentially made him dumb enough to get himself killed when he would have outsmarted the situation any other time.
Dany was progressing toward madness with or without the Varys killing. Tyrion would have eventually landed at that conclusion anyway which was catalyzed by the killing of that one general and his son whom were the last of their family house (can’t remember their names).