It is the type of game you play. Epic v. grounded.
This is profoundly true, and it is a product of level based D20 type game mechanics, regardless of genre.
Compare Traveller and 5e/D20.
D20: characters' hit points scale with levels, creating characters who are effectively demigods who are greater than mortal men. This creates situations that are simply nonsensical, like a player character killing the entire startown police department with a +5 Jawbone of an Ass.
(No paintbrushes were harmed in the making of this video.)
(Public Service Announcement: When the Hebrew guy whispers "God, give me strength." it's time to call it a night.)
Or destroying an entire installation with a double-damage backstab +5 Twin-Engine Helicopter Gunship of Manifest Destiny and a +5 M-60E3 Machinegun of Freedom.
(If only this video had an experience point counter)
D20 level based game mechanics inescapably create the situation of extremely powerful brazenly fearless player characters easily defeating hordes of ordinary opponents, except for a limited number of boss enemies or big bad evil guy characters, which must be limited or the encounter becomes 'unbalanced'. These game mechanics also create the mindset that all the environments and characters the GM creates are just there to be smashed for experience points.
Traveller, D100/Chaosium, and many other non-level-based game systems:
Character hit points do NOT scale with character advancement, because character advancement occurs through skill improvement, loot, and gear. Characters remain vulnerable. This requires players to use their heads and not rely on their level bonuses to destroy hordes of enemies. There is plausible cause and effect. There is plausible FAFO, and this forces players to interact with the adventure in a reasonable intelligent way. There is no requirement for carefully balanced encounters. Characters need only use a skill successfully to advance that skill, so there is no need to constantly "win" encounters, and this
frees characters to attack or withdraw as they please. There is no requirement to gain experience points to advance, so there is no incentive for the players to destroy everything the GM sets in front of them.
Non level based games don't have silly mechanics like roll a saving throw for half damage and other such abstractions. Instead the game mechanics force players to think about how their characters might be able to escape some damage, and they give the GM the freedom to decide whether it works or not and how much effect it has.
Non level based game mechanics require players to use their heads and interact much more reasonably with the game setting, because their characters are still as vulnerable as mortal men. This is the opposite of D20 systems, in which players are accustomed to defeating enemies in balanced encounters. This is why many D20 players have a hard time adjusting to other ttrpgs, and why many of them prefer to return to D20 games.