Not all players are going to stick for the endgame. You make it sound extremely negative, but this is pretty normal and how the vast majority of games work. After a number of hours, players will leave for something else. Few people will stick around and play forever. It's not even a live service game as content updates are very few and far between.
Look at Wukong, it peaked at nearly 2.5 million and yet daily numbers are below 40k. Again, this is normal and how the vast majority of games that aren't fortnite or CS work. It's fine if you didn't like the game, but I'm not sure why you're trying so hard to paint a negative picture. The last update was well received.