Here's a fun test you can try at home. Get someone who is not familiar with TW games, make them play everything from Shogun 2 to Troy in random order, and ask them to rank them from oldest to newest. I can promise you that none of those people would be able to get it right, and certainly very few people would put Troy as the most recent.
After decades, the AI is still broken, the animations are still lazy, and the overall result feels more and more like one of those free-to-play mobile strategy games.
Which begs the question : what are CA employees doing all day? How can so many people spend so much time on the same software and make so little progress that most people would actually believe it's actually getting worse and worse every year?
PS: I just rewatched the "Total War: Rome II - Carthage Battle Gameplay Demo". Can you believe that was 8 years ago? CA if you're listening, I'm still waiting to play the game featured on that trailer.