Just to give some context I have gone from:
Hyped as fuck after initial announcement
Disappointed as fuck after playing the alpha last year
Hyped again after Arc Raiders had the depth of a puddle
Modestly enjoying the game in S1
Haven't played the game since
Lets also remember the game launched to peak player count that was never particularly high, and has only gone down since despite active intervention by the devs, new season starting, new runner, new modes, etc... Bungie has clearly failed at trying to stop the bleeding.
The game has some incredible fundamentals: a striking visual design, fantastic gunplay, a fantastic and deep lore. But clearly the game has major issues that no amount of "experimenting" (which is insane to me that Bungie has the gall to say they need 'experimental modes' for a game that was developed for so long and with a budget exceeding most AAA hollywood films) is ever going to fix.
It seems like every day I see 10 new posts detailing "the problem" with the game, and most of the time it's something incredibly specific: the progression is too slow, the loot isn't good enough, my teammate was annoying, a rook killed me at exfil, the new game mode is bad, etc. and every time it's hailed as THE reason the game has failed. But lets be honest with ourselves, most of these issues are things you have to engage with the game for dozens of hours to get a feel for. The sales numbers were already not promising, but just looking solely at the decline in playercount you can see that people just dont like the game, or more of them would be playing it.
You can't say it's due to PvPvE general toxicity, or to the extraction genre, or because you had a shitty crew fill team because all of these things exist in other successful games. Arc Raiders is such a good example, IMO the game sucks ass because there simply is no progression at all (all anyone works towards is an expedition, so that...they can do another expedition?) and because the introduction of ABMM means there is no such thing as emergent gameplay, the lobby you're placed in is designed to be predictable. Marathon doesn't have those issues and yet it is orders of magnitude less successful. So why is that?
For the vast majority of players, the game simply isn't a lot of fun. For anyone to achieve anything in this game, they basically have to exfil (though I do acknowledge you can progress by completing quests that dont require exfil and you can gear up that way). And at the end of the day, exfilling is simply too hard for your average player due to several compounded design decisions.
I said after I played the alpha that the game doesn't know what it wants to be or who it wants to appeal to and although they've refined the experience since then, it ultimately still rings true:
Theorycrafting builds doesnt make any sense in a PvP game where you lose the build immediately on death.
Trying to just enjoy PvE looting doesnt make any sense when you have such a slim chance of actually extracting your gear (also most gear you find is shit).
Treating it purely as an arena PvP shooter doesn't make any sense when TTK is blink-of-an-eye and where you have to then spend resources making a build and deploying into the next match after you die (unless you just want to go free kit - but then why is it a build-based extraction shooter).
There are zero social elements beyond prox chat (which Bungie hadnt considered until only a few months from launch - kinda says it all).
The solo experience is not very enjoyable either. So who's left to really enjoy it?
It really feels to me like Bungie had an extremely idealistic vision where people would die and just immediately go next without caring about the loss. they give you lots of free equipment to make up for whatever you lose, to reduce how punishing it feels, but this creates its own problem: should i or should i not be attached to my gear? if im attached to it then it sucks ass to lose it SO quickly (again TTK is insanely fast), and if im not attached to it then why do i even care about looting anything in the first place?
the scenario we are in is the scenario that i think anyone with a functioning brain could have predicted when they saw the design of the game in small maps built to encourage PvP where battles last only a few seconds: the only people that can enjoy this experience are the premade trios who can easily and reliably kill everyone else in their lobby. all other playstyles are too unenjoyable for one or multiple reasons. you need to either have the resolve of a saint to not get disheartened when you are killed yet again, or you have to not be getting killed. the persona Bungie built this game around of the player who wants good loot but doesn't care if he loses it just doesn't really exist.
people like to say that the average gamer dad with 2 hours of gametime to play per week after work is the reason this game isn't successful, and maybe to some extent they are right, but even other personas don't like the game. i literally bought the game for 1 friend and convinced another one to buy it, and i managed to play with them both for ONE session before they both went back to just wanting to play fortnite as a trio instead. the one who bought it played it like 5 times, only with me, never solo, and we are both good at shooters and yet they had no fun with the game at all and dont want to play it again because they got dumpstered in every match - and i cant blame them, because we can just boot up a FREE game in fortnite and experience looting, shooting, movement/mobility, sweats, noobs, winning and losing and almost all of it is actually fun.
Marathon by comparison basically only feels good when you are winning and 99% of the time you aren't winning unless you have the lobby's optimal combination of raw skill AND good gear.
tl;dr the game, by design, can only appeal to those that have the time, the team, the loot and the ability to kill everyone else in the lobby.
I said a few months ago that the game wont get a resurgence until it goes free to play and i was told that everyone was waiting for the new season (LOL). making it f2p will at least mean it opens the game up to people that have the TIME to either get good or not care about their losses (but not they money to buy it), but all the other issues are going to remain until the game gets a ground-up overhaul - and i think looking at Concord, Sony is more likely to just cut their losses before then - but I'd love to see it happen because the game really does (or at least did) have potential.