Or he tricked us all.So they can have a useless conversation with Cersei? Tyrion is not good at war strategy.
The truth is:
Tyrion is the main villain

- Yes, he brought Daenerys to Westeros. But only to deliver her to Cersei, after she defeated the Night King and the undeads, after she lost 2 of her dragons (the second one because of the trap, Tyrion built).
- Then he devided her troops by splitting them (land/sea).
- He stopped Varys from turning on Daenerys and support Jon - because he needs a little more of Daenerys in an open conflict against Jon. He told the secret to Varys, because he knows, Varys will tell Daenerys - that Jon talked to his sisters and betrayed her. So Tyrion makes sure, Daenerys first eliminates Jon, then is weak enough to be destroyed by Cersei.
And in the end, Cersei & Jaime sit on the Iron Throne, have their baby child, Tyrion becomes their hand and is the "true ruler" of the seven kingdoms. All other main houses are destroyed, so they can put their own people into the right positions, and everyone is happy

[Except GRRM, for what they did to his world]