I can think of many reasons why this is the best infection used in any halo game.
First off, this was the first halo game to have armor abilities, so the humans were able to sprint and the zombies could use evade (or sprint if playing alpha zombies).
Second, better map design made this the best one. Okay, it might seem a bit unfair to use halo reach’s maps as a reason, but just go back to halo 3. Most of halo 3’s maps were big team battle maps like Valhalla and rat’s nest. In halo reach, bungie used only the small maps for infection. This created a gamemode where you could have loads of zombies come at you at any moment, and one where you could kill zombies a much quicker pace. In halo reach you were less likely to survive a whole round.
And lastly, not too fast paced. In halo 4, Flood replaced infection. The flood were much stronger than the zombies in previous games, and you could take out all of the survivors with a quick respawn time, shields, and the armor abilities like thruster pack and promethean vision.
So yes, I believe halo reach had the best use for infection.