I told you
TNN's attempt was foolish and naive and would obviously fail. And it failed.
I had bad starting location and my ally totally failed me. I could have lived there maybe forever though and helped TNN win, if he wanted. But he was too afraid to try to win the game.
Arrogant diplomacy with Ulm was the right thing to do - he was extremely weak and had easy land to grab. His armies died like flies and he let me besiege his cap for ages, while having 3x more resources and forces. And an ally that I did not have by then. So Ulm was easy picking and there was no need for me to offer him anything or a chance to let him gain from lands he conquered.