Apart from Master Chief Collection and Campaign Evolved, I haven't touched a post-Bungie Halo game, so I can't really comment on the quality of 4, 5 or Infinite. From what I've heard, 4 had a divisive campaign and horrible multiplayer, Halo 5 had decent multiplayer and a terrible story, and Infinite was heavily flawed.
What I can say is that 343 Industries fucked up hard with remastering the old games. Not even Rare (a development studio with a similarly bad reputation for pumping out shit game after shit game under Microsoft) have managed the feat of fucking up a remaster. Halo 1 Anniversary genuinely has updated graphics that do not align at all with the level geometry, and nowhere is this more obvious than in the Truth & Reconciliation mission where you had to sneak past Covenant forces, and if you were playing on the updated graphics, they could see and shoot you through boulders.
The studio rebrand and switch to Unreal 5 was a huge gamble that clearly didn't pay off, because Campaign Evolved had terrible gunplay, glaring bugs, prequel missions with bad design and more exposition than a Shounen anime, and a redesign of Cortana where she has an incredibly masculine jawline and genuinely looks like Jerma985 wearing a wig.
I once saw a comment on Facebook about how the Halo Studios logo looks like an ODST being pounded in the ass with a giant dildo and I genuinely cannot unsee that image. It's also a very fitting metaphor for what they did to the Halo franchise.
Disbanding Halo Studios, waiting for Marathon to inevitably fail and then buying Bungie from Sony for chump change is probably the best thing Asha Sharma can do with the franchise right now.