Their complete lack of interesting custom games is what killed it for me.

Halo, for me, was about forge and messing around in fun game modes people came up with. Releasing Halo without forge and with bare bones custom game tools is like selling a car without seats.

Halo infinite failed because literally half of it's content was garbage. A bunch of new guns, most of which sucked, a bunch of new maps, that weren't impressive, and genuinely game modes that were so boring and bad, my friends and I gamed them to get them over in a couple minutes instead of the normal 30 minutes it would take to play out.

It was also really glitchy, really poorly optimized, and full of GARBAGE microtransactions. It was like multiple tens of dollars for a different set of armor, while previous halo games arguably pushed cosmetics as an awesome thing and an actual status symbol because you couldn't buy them, only unlock by completing challenges.