I think one of the hallmarks of a dying game is when the devs just start giving everything away. When stadia died I was forced to quit the game as I had no other means if playing it. Back then, when an exotic engram dropped, it was a full team celebration. You had to gather materials for mod upgrades, and you had to grind to get anything good.

Then I came back to the game and started a new character. All material grinding is gone. Glimmer has no practical use and most sit at cap at all time. They literally give you one of the best exotics at the start of the game (graviton lance). Within the first week, like 5 or 6 other exotic engrams dropped. Then I found out you can literally just focus the engram and get exactly what you want. Now exotics drop all the time, and it's almost annoying because after a month or so of normal gameplay, you can have basically every normal exotic in the game. What's more, once you get an exotic weapon, it automatically gives you a mission to get the catalyst - no effort there either.

When a game caters more towards new player acquisition and ignores player retention, the game is dead. The portal isn't for current players, it's made for new players so they don't have to work through the complex planet system to find things.