Short rests to me or heroic because they allow people to heal without magic and keep the action moving so literally someone could be like a Conan, etc and keep battling and keep going through an adventure without having to heal.
Nobody can take a short rest to
heal, though. Not without magic, at least. In 4E or 5E, you can take a short rest to recover HP, but that's just catching your breath. You could also take a short rest to catch your breath in older editions, but it wasn't tied to the HP mechanic.
The other change that they added to the game, alongside fast healing, is that enemies became
much more accurate and combat became
much longer. In 2E or 3E, Conan could breeze through half a dozen battles without stopping, but it would mostly involve easy fights where he doesn't really get hit at all. In 4E or 5E, Conan can still breeze through half a dozen battles without stopping; the only difference is that now his Hit Points are going up and down. It's the same narrative taking place, but with different (unnecessarily complicated) game mechanics for it.
In my experience, cantrips which is a carry over from At-will spells from last edition (Thank you 4E!) are a great addition to the game because when PCs play a caster they want to be a caster not a crossbowman.
Some people want their casters to be one-trick ponies who can
only use magic, and can't do anything else. Coming from older editions, I find that to be a very limiting perspective.
A wizard isn't supposed to be
less than a non-wizard. You don't
forget how to use your hands, just because you've learned to cast spells. A wizard is a person who has
added magic to their skill-set. Of course they should be able to fire a crossbow! I mean, what kind of weird entity isn't even capable of using a simple mechanical device?