https://en.wikipedia.org/wiki/Nintendo_hard#:~:text=In video games%2C the term,%2C and Battletoads (1991).
I started gaming back in the 80's before there were difficulty sliders. overcoming nintendo hard difficulty just became a natural thing for me and its stuck with me even today (its a big part of the reason i get so frustrated playing a f2p game like world of warships; the mechanics aren't that complex and the way some people screw up matches because of, what is to me, an obvious error on their part, just causes a part of my old school gamer soul to shrivel and die)
Nowadays I usually crank the difficulty up to max on arcadey type games like call of duty or battlefield. strategy games, like total war warhammer, i tend to sit the difficulty in the middle. reason i do the arcade shooter type games on max is because winning is mainly a matter of twitchy reflexes, and the reason i do strategy games in the middle is because winning is based on your thought process (e.g. your strategy). shooter games up the difficulty by making enemies bullet sponges and do more damage; the trick to winning is just to stay alive and land your shots; but with strategy games difficulty increases are because of giving the AI buffs (or nerfing the player), and with enough of a player penalty bad rng just can't be overcome. shooters are less rng dependent than strategy games, so with good reflexes you can win no matter how much the bad guys are buffed.
finally, rpgs... these i tend to play at mid-high difficulty. especially ones like skyrim which have elements of fps play in the combat mechanics; but i don't max out the difficulty because i want to push the storylines forward and my time is limited so i can't spend the time to min-max my character builds or cheese fight mechanics.
side note; what people think of as cheesing a fight nowadays was once intentional. back in the day there would often be only one specific way of winning a boss fight. growing up, in almost every game you had to do something like stand in a certain spot where you couldn't be hit or something and just keep plinking at the boss's healthbar till you won, and that was by design. today, that sorta way of beating a game is considered abusing the game mechanics.
like dark souls is to me an old school nintendo hard game because its boss fights are basically just pattern recognition (just like the old 8-bit nintendo games). sure, they're frustrating until you learn the pattern... but i don't consider dark souls a hard game because just like the old games, once you learn the pattern and timing, you can get through it easily. that's why you can find people playing dark souls blindfolded, just like you can see people doing old school nintendo games blindfolded.