The population is decreasing, huh?

I started playing around last year to earn points, and when I started again on a new server for another point-earning activity, I was surprised by the drastic decrease in population! My territory has so few people in alliances that it feels like one alliance would be enough. Also, back then, I was constantly on edge, surrounded by other players on all sides, but now, at a glance, there's only one player's castle nearby. Did they move on to another 'Romance of the Three Kingdoms' series game? Well, I like Three Kingdoms games, but I also like Sengoku period games, so I understand how people might have moved to 'Nobunaga's Ambition: Shinsei'~! Especially since they seem to be doing a collaboration with Samurai Warriors right now, it makes sense that players would focus their efforts on Nobunaga's Ambition (⁎˃ᴗ˂⁎)♬*゜