Soulslike is when game hard, 3D, combat and boss fight focused, with dodge mechanics and real time combat. Or are you gonna tell me Super Meatboy is soulslike because it's hard?
It seems to me that the most distinctive feature is the save mechanic that essentially splits the game into levels where you can only save your progress when you reach a campfire.
For example, Jedi: Fallen Order is a soulslike because it has the same mechanic (with meditation circles instead of campfires), despite being SciFi themed. It does also have all those other things you mentioned, but arguably, so does Skyrim, which is definitely not a soulslike.
It seems to me that the most distinctive feature is the save mechanic that essentially splits the game into levels where you can only save your progress when you reach a campfire.
By this definition, Demon's Souls is not a soulslike.
At least I can fight Malenia 50+ times without any tedious things in-between. If you die three times at a boss in an 80s game, you’re starting that game over. I would say that if 80s/90s games had similar qol improvements then most of them would not be as hard as souls games.
Yeah, most of the challenge back in the day was clunk, lack of information, and game design derived from arcades, where you had to die so that you'd use more quarters.
It's not that Souls-Likes are hard, it's just death is a mechanic in them. We traditionally associate a death screen as a loss, in that sense you have to redo a section of a game with no additional reward. But in Souls-Like games, death resets the enemies but you can get your lost experience back on top of the newly acquired one. This means that at some point the section should become trivial because you're potentially over-leveled. A Souls-Like can kill the player fast because the return to the point oft death is also fast and rewarding.
That's in my opinion is what makes a Souls-Like a Souls-Like, it's that gameplay is paced with player death in mind.
They are and in a weird way they aren't... I didn't play a WHOLE lot of souls likes. I finished Elden Ring, am pretty far into Dark Souls 3 and Lies of P, played some Dark Souls 1 and 2.
The thing is: Yes, you die very often for sometimes maddening and sometimes silly reasons, but you get better: The mechanics just start to "click", you earn just enough souls to afford another level up or some piece of equipment, you learn the positioning of you enemies, their attack patterns, timings etc... And slowly and steadily you progress: Around the next corner, to the next boss, you beat the boss. Then you come back to an area you already visited and murder everything...
And if you can't progress in any way there are summons (players or NPC) that can give you an edge or you try using consumables you forgot about...
Especially the Fromsoftware games have managed to hit that sweet spot where the game is challenging but (most of the times) doesn't feel unfair or broken. It's just an amazing piece of game design and you should try it. :)
It's not the difficulty, but the time commitment the difficulty requires.
I enjoy games that are difficult that allow me to retry 5 seconds later. It's why I can enjoy Super Meat Boy, Neon White, VVVVVV, etc despite my busy schedule that affords me maybe 2 hours a week for gaming.
For a Souals-like you have to spend way too much time retrying and attempting to get good.