Here it is, Halo Infinite.
I made a list of all Halo campaigns sorted from best to worst (You can find it in my profile with notes to every single one) and very early I already knew it won't beat 3, 2 or 4, but I wasn't sure if I put it above 1 (and therefore ODST) or not, I decided to not do that.
Too repetitive was the gameplay, just 1 real biome, just a handful of old enemy types and story missions mostly being in the same looking structures. This ain't it chief. Yes it has one of the best pure shooting gameplay yet and it's so fun to play, but that doesn't make up for all the other flaws. Heck, even the pure open world gameplay isn't that great with a map mostly not made for cars at all and one simple grappleshot that feels limited very fast with the feeling that you should get so many more gadgets that help you to traverse in a cool way, but they never come, it never changes.
After all this time, after all the waiting, that isn't was I was hoping for. The actual story was well told and I liked it, I give it that and that makes it definitely better than 5, but I can't go any higher.

All in all, disappointing.