"Itzal is better than all other archwings and it's too strong"
Itzal isn't better than the other archwings, the others don't have a place. Itzal fixes the 2 major problems of archwing, movement and loot. With itzal you can stop on demand with it's 2, while all other archwings either have to slow down to a stop or smash itself into a wall to kill it's momentum. As for loot, the innate vacuum range is horrible while Itzal is able to pull in more loot at a much larger range with it's 3. When a game is all about loot, and there is only one way to get loot. People use it. Remember when Vacuum was only usable on Carrier?
With that being said, most archwings have some use when it comes to archwing missions. Odonata is meh but is the best option for killing Jordas because it has a damage buff, and it is in the most need of a rework. Elytron is best for eviscerating enemies, and Amesha is best as a support role and for defense missions. The problem is that support roles in Warframe is mostly useless aside in from specific scenarios when it comes to farming. So Amesha won't be used much.
"Itzal is the only used archwing in open world"
As it should be in the current situation, DE has made both factions in the open world have instantaneous ways to disable the players archwing via anti-air rockets that upon damaging you, rips you out of archwing. This makes all archwings (aside from Amesha because it has invulnerability and can avoid the anti-air) for in-combat scenarios useless. Hell, the latest "tactical alert" we had I used Amesha, and how did I play. I ran up to the coolant, pressed 4 spammed my 2 about 2-3 times. Then flew off 50m behind a rock to avoid the missles.
Let's imagine if you could use archwing in combat. Elytron's damage is only useful vs archwing enemies because of how severely nerfed they are. Archwing enemies are a joke, they do no damage and have no health or armor. If you ever played The Jordas Verdict you would have seen level 80 archwing enemies and laughed at them for being a joke. When you take the current enemies with scaling and armor, and then reduce Elytron's range to a insignificant range. Take into account that enemies in open world spread out a lot, and further more that Elytrons main source of damage, it's nuke, has damage fall off. There is no wonder why no one plays Elytron. It does no damage, has no range, and is overall useless in open world. Odonata is again too niche to be useful, and Amesha is fine if you want to sit in a bubble and snipe things. But most of the time you'd rather just swap to Warframe and have fun using abilities melee and guns.
Because of these situations, it's no wonder people only use archwing for transportation. And guess what is by design, the fastest archwing? Itzal.
"But Itzal is faster than K-Drive!!!"
And? What is your point? Realistically when you take into account that K-Drive is on the ground having to deal with ever changing terrain. Where you have to turn, jump, and navigate around. Of course the thing that flies through the air would be faster. Just like in real life, airplanes are faster than a car. And yes, I know we're in a game. So why not make K-Drive faster? And be able to keep up with most archwings? It shouldn't compete with Itzal blink(Because as design it should be the fastest thing in the game), but it should compete with archwings sprinting. Nerfing Itzal to be more in-line with other archwings or K-Drives just further asks the question "But isn't that suppose to be Itzal's identity? The fastest, sneaky, and squishy archwing?" Why not make archwing's more usable in open world combat, and K-Drives faster (If this was really a real point and not a joke) than nerf the identity of an archwing that has had no problems for years until recently. That way you promote more use of other archwings, and people who love K-Drives get to go faster.