343 has never been good at managing a Halo game. Not sure what OP is referring to specifically but 343 has made tons of awful decisions with the franchise. One thing that always bothered me with infinite is from what I remember the game has an enormous amount of tech debt because Microsoft loves to hire temporary contract workers so by the time a new contractor was hired and brought up to speed on the new engine they were developing/had developed, they barely had time to do much before having to be replaced with another contractor, which makes me feel awful for the poor developers hired on these temp contracts.

In a nutshell: corporate greed. The only part of the game that was live service was the paid cosmetics.

At launch, their entire idea of more ‘content’ was just visual cosmetics. If you look at their communications at the time it will all make sense.

They constantly referred to an internal ‘live service’ team separate from the rest of the game, and that team was effectively the ‘cosmetics team’.

People talk about contractors, but this was the real problem. They thought they could get away with barely adding any real content and selling tons of cosmetics.

Amazing core gameplay, but a lack of content. The game was pushed as a half-assed live service game, but they never released content at anything close to a live service rate. Coupled with pretty horrendous progression/aggressive MTX pricing at the start, and well...

In this case, 343 management (since replaced) used 18-month contractors to perform the engine overhaul and build the game across the several years it was in development in order to save a buck, which in turn meant there were countless holes in engine knowledge and the engine was spaghetti code. That resulted in unfinished tools for months after launch and slow game development as a result, as well as major desync issues where you could be in an entirely different area on your screen than you were according to the server. The monetization and FOMO was also off the rails, with absurdly difficult and annoying weekly challenges that were necessary to grind the battlepass and unlock anything for free. Basic color sliders were taken away in favor of "armor coatings," and as such, to date I still cannot recreate my Halo Reach Spartan even though I have all the armor pieces necessary thanks to the Season 1 battlepass (which is the only battlepass I own, since I bought it during the honeymoon period and it doesn't contain any credits to buy the next battlepass). They did successfully commit to having battlepasses that don't expire, but only if you paid for it, otherwise it still expires and this was only mentioned for the first time like a week before Season 2.

The list kinda goes on and on, but the tl;dr is that devs and players alike both got hyper-fucked by Bonnie Ross.

Also the fact that campaign wasn't even available on launch. I was pretty excited for some co-op campaign but never even went back after they implemented it months later.