I know, I know, I'm posting this on a community dedicated to Helldivers 2, statistically the answer I would get just from the title is "yes".
Circlejerk aside, I can't think of any other live service game that is a fair comparison.
The closest one I can think of is Deep Rock Galactic, which (ATTOW) I've played for 1.2k hours, compared to HD2 (1.001k).
But then, even though I think DRG is a qualitatively equal game AND technically also a live service game, if we're simply judging the live–serviceness(?) of either game, HD2 comes out on top: I bought the game way after the Malevelon Creek plotline, and even though I was late to the party, it still feels like shit keeps happening every month or two, while I haven't played DRG in 2 years and AFAIK it's still... there (mad respect though, rock solid game).
The other three LS games I've ever played for significant time spans are Team Fortress 2 (1270h), Destiny 2 ^(holy^ ^shit^ ^so^ ^many^ ^2s)^ (170h) and Sea Of Thieves (160h (I've got a friend with >3k h? wtf?)).
TF2 is... I mean, it probably holds up, idk I haven't played it in 6 years or more but I'd hardly consider it an ongoing game (PLEASE correct me if I'm wrong);
Destiny 2 is, as far as I know, the most relevant AAA comparison with a reasonably strong season–spanning story and MEH, my brother gifted it to me (two seasons, in fact) and they both felt like a chore to keep up with;
Sea Of Thieves is... have you played it? It's jankier than the Spear was 6 months ago.
I never even considered playing Marvel Rivals, a currently popular game, but...
HD2, on the other hand, ~~never misses the mark~~ misses the mark quite often but in a funny or spectacular way.
Maybe it's just me playing every other evening and having warbonds and events not too hard to keep up with, with eventual SC farming every now and then, but off the top of my head I've been through:
- The appearance of the Jet Brigade (at the time I just thought jetpack commissars were simply regular enemies (maybe they were idk));
- The gloom;
- The DSS construction;
- The DSS perpetual 380 (underrated af idgaf fite me 1v1 Rust snipers only);
- Meridia ~~(I was born there in 2117, honestly I'm excited to get back home and hug my wife)~~;
- New fire warbond (where they nerfed fire? wtf?);
- New warbond;
- New warbond;
- ~~The predator strain actually nvm I genuinely refuse to ever play against them, not fun, gg bb, these guys are bullshit~~
- HOLY SHIT A COMPLETELY NEW FACTION ATTACKED OUR PLANETS THIS IS ABSOLUTELY UNEXPECTED AND I MUST UPDATE&BOOT THE GAME IMMEDIATELY ~~(I looked up the first game's lore beforehand and I knew 100% this was going to happen, but still)~~, also new warbond;
- New warbond (idgaf I'm bringing the One True Flag on a Super Helldive and you ARE going to put up with me);
- Flame brigade (idr when they were born but I loved them)
- ... Super Earth? Seriously, I honestly did not see this coming, maybe I should have, but I didn't.
- New warbond;
- New warbTHAT IS A FUCKING HALO: CURSED EDITION BLUNDERBUSSond;
- The steam rewiew bomb cape
- The Steam review bomb cape
- The Steam review bomb cape
- The Steam review bomb cape
- Xbox recruits (finally my brother and I can play together with something that isn't Sea Of Thieves or Destiny 2)
... and we're still going.
The point is, in an age when the pre–StopKillingGames videogame industry defines "live service" game as a non–government owned legal money printing machine, to me Helldivers 2 is the only working example of an actual living game, and... a bit of a miracle.
A Sony funded live service gold rush miracle, but hey, even God™ got gotta earn that bread.
... relevant to the last paragraph: EU citizens, go sign the SKG petition right now. Super Earth demands it.