I agree that the best way of addressing disruptive behaviours is to simply talk to the player.
However, that's kind of skirting the issue. What I and others have been saying is that actions should have logical outcomes. The falling off of cliffs and guillotines and whatnot are just examples of that.
That's not exactly what some people in this thread have been saying though.
The argument has been that the reason for jumping matters. That if a DM agrees with the players reasons for jumping - the character takes standard falling damage. If not, instant death is the result.
THAT'S what I have a problem with.
Let's say that there is a running wood chipper blocking the character's path. The player decides his character will dive through the wood chipper to get to the other side. Assuming the character doesn't have super powers that would enable this, I would warn the player that doing so would result in their character exiting the the other side as a very dead red mist. It doesn't matter how many HP you have, you can't pass through an active wood chipper and survive.
That's an old school approach. Tomb of Horrors, for example, is filled with situations where if the PC so much as walks in the wrong direction - instant death.
5e has shied away from it. Generally DCs and damage are assigned.
If a standard 5e adventure had a woodchipper, for example, it would likely did a bunch of damage (say 10d6) - with the reasoning that 10d6 would kill any regular joe. But that a high level adventurer could figure out a way through it - damaged but not likely killed.
Based on the fact that high level adventureres are not, in fact, average joes.
Most likely it's a simple misunderstanding. The player thought it was a death trap they could parkour their way through, whereas it is actually a guaranteed death unless disabled. But there are some players out there who think of HP as a force field or ablative dermal reinforcement. Those players literally think their high level character should be able to dive through a wood chipper and just take some HP damage. At my table, however that's not how it works, and I would make that clear.
It's your game, play how you like. Especially as long as you're consistent about it.
That said, 5e was built upon the assumption that magic items aren't required. As such, you can't assume their existence, even in a high level game (although I agree that most games do use them). Additionally, I strongly disagree that HP are representative of something like an indestructible magic shield:
A) not every high level character has a magic shield. I'm fairly generous regarding magic items IMCs with the exception of shields and armor, which I am downright miserly about.
B) if you take away a high level character's gear (he's captured by powerful enemies and stripped) his HP don't change one whit. That says to me that his HP have no direct relationship to his gear.
I'm not actually arguing that HP have any relationship to gear. A PC could jump naked, or not, and falling damage should be the same (obviously not counting items that actually mitigate falling damage).
The "magic shield" thing was just a (bit muddled) attempt at saying you can explain the lack of instant death by saying a high level character can maximise use of gear at hand. But, it's nut necessary - and muddles the issue.
Additionally, Captain America has superpowers that put him well above non-powered humans in terms of physical abilities. He may not be the Hulk, but he can do and survive things that an unpowered individual simply cannot. I'm pretty sure that very same movie opens with Cap lapping Falcon multiple times while on his morning run. Falcon is no slouch, assisting Cap during the climax of the movie, but we wouldn't expect him to be able to do or survive the things Cap can.
I'd argue that high level PCs, ones that can take a hit from a cloud giant or survive an ancient dragon's breath weapon - are much closer to Captain America than Falcon.
But again, that's not really the issue. There's no question that a high level fighter has the HP to survive a 200 foot fall. The issue I have a problem with, is A DM deciding to not apply the falling rules because they don't like the player's reason for having the character jump.