Is Hex worth it at high levels?

[GeneralVryth]

5e is actually quite clear that the CASTING of the spell is what requires components.

Yes the book is clear that casting spells requires components, no has disputed that.

Using actions granted by the spell - including shifting the effects to a new target - only require whatever behaviors and actions the spell says they do.

True in a sense, the thing in question has always been an interpretation of what they say. What does the action in question look/sound like? By extension is it impacted by things that affect them.

Call lightning does not require verbal nor somatic components after the initial casting. It is used explicitly by Wild Shape as an example of an ongoing spell you can continue to use the action granted by, when Wild Shape also explicitly forbids casting of spells (and, when you later gain the ability to cast spells in Wild Shape, it goes out of its way to describe how wild-shaped Druids substitute animal motions and sounds for the usual components).

The Druid text is the first interesting piece in all of this. The not casting spells piece doesn't apply because we weren't talking about that in the first place. The easy resolution is they can preform the necessary pieces of the action in beast form, just like the Beast Spells ability grants them that exact ability for the initial casting.

The only requirement to call down lightning on subsequent turns is that the spell still be active and that you use an action to do so. No V or S components required.

The same is true of shifting hex or hunter's mark to new targets: you just use the bonus action they require to perform the shift. You do not need to obviously cast anything, because you are not casting the spell. You are taking a bonus action the spell allows you to take.

This is all assumption.

Let me add another variation on this. What does taking the Help action look like? Does a character stand around doing and saying nothing and an adjacent character suddenly gains advantage? The book doesn't say you do something anymore than Hex does ("lending aid" versus "cursing"). But, that leads to a pretty silly game world if you follow that thought.