Is Hex worth it at high levels?

[Segev]

No where in the Help does it say that a DM decides if help can be meaningfully given. Here is the action:
Help
You can lend your aid to another creature in the completion of a task. When you take the Help action, the creature you aid gains advantage on the next ability check it makes to perform the task you are helping with, provided that it makes the check before the start of your next turn.
Alternatively, you can aid a friendly creature in attacking a creature within 5 feet of you. You feint, distract the target, or in some other way team up to make your ally’s attack more effective. If your ally attacks the target before your next turn, the first attack roll is made with advantage.

There is nothing about DM judgement in there at all. Now of course I think DM judgement is given/required but it's not stated.

Fair enough. I specifically recall reading somewhere that the DM adjudicates whether you can meaningfully help with a given action, but I am far too lazy to go hunting that down, so will conceded the point. I instead draw your attention to the first sentence: "You can lend your aid to another creature in the completion of a task." This actually does specify that you must actually do something that helps; it says "you lend your aid." No, that's not terribly specific, nor should it be. But it certainly draws a different line than the spells you're trying to add "recasting" to.

I reject your terminology of "recast actions," by the way, because it is clearly drawing you to view the action as "casting" in some fashion, when it very much is not. We know it isn't "casting" in any sense because druids cannot cast spells while wild shaped, but can use the actions specified by spells that are already in effect. Note how the rules never call it "recasting" the spell, but refer instead to taking actions the spells permit. You may as well call it "recasting" when somebody who is under the effects of fly lands, spends a round on the ground, and then takes off again, if you call calling down a second, third, fourth, etc. bolt of lightning "recasting" call lightning. You may as well say that the recipient of dragon's breath is "recasting" the spell every time he breathes fire (or whatever energy he breathes), despite the fact that the recipient need not even be the original caster!

There is no "recasting" of hex, and your terming it that makes no sense unless you're presuming your conclusion that it is "casting the spell again." It isn't. It is a function of the spell to allow you to transfer the curse it places to another target. In effect, if you do a fine parsing of hex, casting the spell places a curse, and it is the curse you are moving from target to target. You are not creating a new curse, thus you are not recasting the spell.

Metamagic is easy, it's not an action. It's a modification on an action.

Why is that relevant? An action doesn't have to be anything visible. A Subtle Spell quite specifically is meant to be invisible and undetectable (which is why adding things to metamagic would be ridiculous), but it takes an action. Same with transferring the curse created by hex, or directing another bolt of lightning created by call lightning's ongoing effects.

So you can default to the requirements of the action in question (in this case spell casting components since you're casting a spell), unless of course those requirements are modified, by something like Subtle Spell.

You can default with hex to the requirements spelled out to transfer the curse, too: nothing except spending the bonus action to do it.

It doesn't say anything though. Which makes your statement on binding the hands either an assumption or a ruling.

The problem is that all of the things you're suggesting go into "recasting" would allow me to bind hands or still tongues to prevent "recasting," and you had to make up additional rules permitting wild shaped druids' beast forms to somehow pull off level 18 class features in order to do "recast actions." Which, again, are your invention; they do not exist. You are welcome to define using actions provided by spells as "recast actions," but if you do, you must abandon the idea that they have anything to do with casting components or even any specific behaviors that are not spelled out in the spell. Otherwise, you are not just labeling something, but attempting to redefine it.