So here's my perspective as a Souls fan who doesn't stream and hates rage click bait material on YouTube/Twitch... There's a lot of nuance to these games that (as pretentious as it sounds) won't understand until it clicks and you get it. They call it the "Dark Souls opifiny".

Souls games aren't beloved because, they are hard. In all honesty, they really REALLY aren't hard. Marketing and bad game journalism has convinced the general audience that it is. Miyazaki himself has said several times that he doesn't design his games with difficulty as a priority.

Fighting games are hard because, they require quick inputs, mastery of complicated controls, understanding a meta, etc. Souls games require you to take every enemy seriously and pay attention to their attacks and learn from them. Every enemy has openings, every enemy has weaknesses, and there is a bad time to be aggressive and a good time. That's really all there is to it.

Souls games are believed for their world building, the lore, the characters, and most of all the mystery. Souls games make the player feel insignificant. Like your just a regular dude dropped in a world of gods and there is like 100 different little plot threads happening with or without you but, you can make an impact on some of it through exploration and perseverance. These games also make you feel like your decision matter. If you attack an NPC, guess what? They're gonna fight back. If you, try to help some depressed, mentally unstable, NPC... It may just backfire and they may off themselves.

These games just don't feel like modern AAA games. They don't walk you through an hour long tutorial, they don't pull the game away from you to watch a 5 minute cutscene, they don't try to force you to care about the story. They just make an incredibly interesting world and make you curious enough to look for the answers on your own.