Obvious, end of the world (and the like) doom clocks sure - but time pressure doesn't always (or even usually) mean that.
my example wasn't even end of the world... it was 1 life, the gold dragon wyrmling.
Time pressure simply means you don't have unlimited time to do stuff.
I can't say I often give unlimted time... but there is a BIG difference between "Hey if you do this fast enough" and "You fail if you don't do it fast enough"
Want to get that big fancy sword from the shop? ok, but if you wait too long someone else might snap it up.
this seems a great example... I can't imagine someone (any not crazy chracter anyway) saying "we are out of healing and big booms, BUT we should press on and take the final few encounters and maybe loose or die so I can buy a shinny toy.
(not withstanding I don't run item shops like that often, but I play under people I can see doing it)
if we finish the dungeon, and get back and someone else bought it (in my games at least) that would be a new hook... is it a friend or foe who has this sword, they must be an adventurer or royalty of some kind.
Heck back in 2e I had a spell storeing sword (spell striking sword was it?) That a player REALLY wanted but it was several thousand gold and the party together didn't have 1 thousand. It was almost 2 levels and many dungeon crawls before the character saved enough to get it... but if someone else had bought it first it would have changed his goal, but not been a major loss.
Want to collect the easy bounty on the goblins infesting the sewer? Great, but so do a bunch of other adventurers.
then even if you DON'T get the bounty you find other adventurers (are they friendly rivals or potential foes or friends to team up with?) this is important (and why I keep bringing it up) becuse if they can be allies then them have the item is almost as good as you having it (more powerful allie) if they are a foe then you kill them and take it sooner or later... sounds like a win win to me.
It's rare that people can do the stuff they want on their own timeline without regard for other things going on around them.
where it is rare for people to have unlimited timelines, having a flexible one isn't...
In MY Experience the difference we are talking is somewhere between 1 hour and 24 hours... now where they may not have 2 weeks to waste, taking an 8 hour refresh shouldn't be that crazy most times.
even worse, on a doom clock hurts SHORT REST classes more. "No we can't take an hour to catch our breath,"