Realm is not dying. How do I know? As DECA are investing heavily in porting it to Unity, something they would not be doing if the game were dying. They might not announce it but the oncoming demise of Flash would be an ideal time to retire the game quietly, if it were not doing well. But the Unity port is pretty compelling evidence that the game has a future well beyond 2020.
All that’s happening is that you are getting tiered of the game. That’s fine and normal. I have spend thousands of pounds on games for PC and console over the years, the vast majority of which I no longer play. I just got to a point where I lost interest in them, even games like ROTMG with no formal ending, which you could keep playing forever.
If the game no longer appeals to you then stop playing. Maybe you will find other games that interest you. Maybe you will lose interest in games. Maybe you will return in a couple of years, to see what has been added and changed. I’m pretty sure the game will still be here if you do.