Ironically enough, in their attempts to make the AI feel more different from each other, they came out feeling more same-y to me. A lot of agendas, both the permanent ones and the hidden ones that get randomly assigned, are... things you can't really control. Meet an AI whose agenda is all about not building tons of improvements, in the 1700s after you've... already built tons of improvements? Congratulations, they're gonna call you up every forty turns to complain from now on. It kinda makes every leader end up feeling arbitrary and annoying. And really petty sometimes, too. Yeah, bro, I know you've been calling me up for the past 1500 years to complain that I have no navy, and it is going to stay like that because I'm a landlocked empire.
Civ V had the issue that other civs were too opaque. They did things, and I didn't know why. It was just a mystery. Civ VI is clearly trying to fix this by giving other Civs clear reasons reasons liking or disliking you, but the reasons don't make any sense. The last time that I played, I was on the same continent as a leader that was big on constant expansion. He wanted to blob all over the map, and by the logic of Civ VI, he wanted me to blob all over the map. "Hey, why aren't you trying to quickly grab all the land that we are trying to grab? We would like you so much better if you were trying to grab that same land that we want!"
It's maddeningly nonsensical, like the naval example that you gave. Even if you hadn't been landlocked, it's still a weird thing for a country to keep bugging you to have a big navy. In real history, the British Empire at its height wasn't running around trying to push everyone else into making big navies. It wanted having a naval supremacy to be its thing.
In earlier versions of Civ, you might see incremental improvements to AI in the expansions, but the problem with Civ VI for me is that I don't like the basic model. In Civ IV, the AI might fall down at times, but the designers were at least intending to have the civs act like civs. In Civ VI, a lot of the most irritating, artificial behaviors are the game doing exactly what the designers want it to do, so I am skeptical it can ever be fixed.
I can understand people liking the game anyway, as there are a lot of interesting moving parts in it. It's just that part of the fun of Civ for me has always been the emergent story. The strange AI choices in Civ VI tend to produce really silly stories. While I can have fun on a turn-by-turn basis for stretches of the game, the overall shape of it is unsatisfying to me.