It’s a reasonable point to raise Bill, but I’d say there is an answer.
The Souls series of games is very good at making you feel like a cunning bastard for doing this sort of thing. Unlike most of games, it’s totally cool with you cheesing it (well, Demon’s Souls and Dark Souls were, DS2 was less like that, and it sucked, so DS3 moved a bit back in that direction again). You can also complete the game naked with the starter weapon - people have - you can’t do that in most games that actually-require grinding, it’s just mathematically impossible. Here it’s always your choice - instead of going with “git gud”, you just choose to “get powerful”. But you made the decision, not some game designer.
You don’t feel like you’re being forced to trek to the other end of the world to tediously wander around looking for “random encounters” which you mindlessly crush over and over to get XP. In Dark Souls, every fight is potentially fatal if you fuck up bad enough - and you probably will at some point. And if you want to gain souls at a reasonable rate, you’re probably fighting something semi-dangerous. So it’s not quite “mindless grinding”, it’s almost more like gambling - can I kill all these and then get back to a campfire and level up? Should I kill some more because they reset when I go to the campfire and I have to fight through some annoying stuff to get to these easier mobs? Should I be kill these slightly harder things because they also drop a resource I want? Plus you’re likely killing stuff for an hour or three, not like, 10+ as can be the case with some games where the maths dictate it.
You’re making decisions and taking risks. Not huge risks maybe, and if it’s bad enough maybe you’ll do something really easy, but probably not.
Plus often whilst doing this, you have another idea, or decide to take another approach, rather than going straight back to the same boss, because DS isn’t very linear.
On top of all this, the combat in DS tends to be pretty fun, and often whilst fighting easier opponents, you actually, genuinely get better at the game, so that’s on top of the power increase. Whereas in some JRPG where you have to grind for 10 hours or more, you, if anything, get worse at the game, forgetting how to do anything complex, and are just mindlessly pummelling the same few encounters which is no fun and has no sense of risk - and indeed in many JRPGs, there is literally no risk.
So yeah, good question but there is an answer.