Excellent point! D&D set up two parallels last season between Tyrion and other characters that never paid off.
First, Tyrion, like Cercei, empowered a group of religious fanatics. Cercei is punished for this terrible decision by walking naked through the streets. She eventually has to blow up the sept to get away from the extremist. Tyrion doesn't face any repercussions for empowering R'hllor followers. In fact, Kinvara and her ilk were forgotten.
Second, Tyrion, like Jon Snow, turned against his advisors to make peace with a sworn enemy. Jon is punished for befriending the wildings by being murdered. But Tyrion doesn't face any repercussions for going against Grey Worm and Missandei's wishes and alligning with the slavers. Dany just swoops in, saves everyone from the slavers, and the tensions were forgotten.
So, yes, Tyrion should be dead. But the writers just ignored that actions have consequences.
