I don't think it's an age issue, it's more that the game has changed in nature. Is it better or worse? Well, that depends on what you’re looking for. You think it’s better, and that’s fair. Personally, I don’t feel the same, but I don't think that's because I'm out of touch. I still enjoy plenty of recent games. If it were a generational problem, I’d probably reject the whole modern gaming industry, but that’s not the case.
Civilization isn't the only franchise to evolve in a way that divides its fans. Take Zelda for example. It started as an adventure game, but over time, it became more and more linear untill it reached a point, with Skyward Sword, where there was hardly any overworld to explore. Skyward Sword was a good game, but it was no longer an adventure game. Instead of dismissing those who missed the old formula, Nintendo looked back at the original NES Legend of Zelda to understand what might have been lost along the way. And it resulted in the wildly successful open-world Breath of the Wild.
It goes to show that sometimes, looking back can also be a good way to move forward.