For people constantly making the highguard/concord comparissions.
Marathon is going to die a slow death. Its player count hasn't tanked like Higuard's did just a day after launch.
Highguard lost 59% of its playerbase in a day.
Concords' player base was abysmally small but it still lost 39% of them in a day, by the second day it had lost 57%
Marathon for context, has lost 24% of its peak base over the course of 5 days. For context the Server Slam lost 61.7% of it's playerbase over the course of the same time frame. It was active from Thursday the 26th and shut down March second on Monday. In that time it went from a peak of 143,621 to 55,762
Arc Raiders ironically had a pretty noticable decline if you look at it's charts. The reason it's not seen as a bad thing is because they started with so many players.
But Arc Raiders on Steam at least has lost 62.6% of it's player base. I'm not saying this to say that Arc Raiders is a failed game, it obviously isn't but I am saying that outliers like Highguard and Concord, while a lot more common, aren't so common as to look at every game and think they will fail immediately on release.
Marathon WILL eventually be shut down, I don't doubt that, but I think, like I have said earlier, that it will be a slow death as Bungie tries to scoop water out of their sinking boat. The game will probably last a year, maybe two, before it's fully dead.
Halo Infinite will be the game it emulates, not concord.
That whole fungus thing sounds a lot like the egregore from D2, a physical manifestation of Darkness specifically tied to memory. There have already been scattered Marathon references in Destiny, so I wonder if they're going in the opposite direction too.
A lot of people don't seem to realize that Bungie aren't all that original and steal a lot of shit from their own IPs. They reference Marathon all the Time in Halo as well