What's the point with that quite lackluster story in Endwalker?

[Dikatis]

Except Kairos was already created, and it was in use by other Ancients in Elpis. It's supposed to be a serious and strictly monitored thing, so you're telling me there's more than one? Or that such a serious thing would be only in Ktsis, at the very top, when it has to be employed by any of the researchers anywhere else? You're telling me it's just is wherever Hermes is, even if he doesn't know whether it's been used or not earlier in Elpis?

What are you talking about? It's a creation. Meaning that anyone given clearance by the chief overseer can just magick one into existence. Hermes is the supreme authority in Elpis and the one who provides that clearance. Of course he just make another one and activate it when he's the one who INVENTED IT. I don't understand why you're so hung up on the idea of Kairos being "present" when literally everyone in Elpis has the power to bend the fabric of reality and magick anything into existence if they can imagine it. It's not even taxing enough for the researchers of Elpis to consider using Kairos a form of last resort. They mentioned it off-handedly as one of the measures they tried to pacify the lykaons.

Or you know, the other more obvious problem with the scene. Emet-selch not just blowing Kairos the hell out of the air. Venat reaching out her hand to try and catch Meteion instead of hitting her with her chakrams or idk, multi-tooling her magic sword into a gun and shooting her down. Or the common Holmgang chains all characters get when they need to restrain other characters (Like the ones Hermes employed just a second ago, somehow, weee).

Implying that Emet-Selch could do that casually with his powers dampened by Ktisis Hyperboreia's security measures (that were mentioned at the very start of the event) and Hermes standing guard over it. There's a reason why Hythlodaeus and Emet-Selch prioritized getting WoL to safety to escape Kairos' range rather than trying to strike down Hermes and destroy Kairos. Hermes took on WoL, Venat, and Emet-Selch at the same time and came out of it without dying and is still strong enough to stop Venat's charge. This is on top of Hermes being a tremendously powerful mage who spams the highest level of wind magic as well Meteor, an "apex magic". What makes you think that Emet-Selch alone could somehow casually overpower Hermes? There's also no indication that Venat knows the same binding spells as Hermes, let alone one capable of keeping up with Meteion who is flying at escape velocity. As for the chakrams? Have you ever tried throwing something while the wind is blowing in your face? Guess what? It flies back into your face. Now try that while flying at atmospheric escape velocity.

You're purposefully omitting context to present a skewed version of the events that actually happened.