New review on OG Fallout.
Hmmm. What makes an RPG or an Immersive Sim is kind of an open ended question, like how deep is a puddle. You recognize systems that belong to it and you can pick it out of a crowd against other genres but when comparing two different games, it's like comparing two different apples at that stage.
But what makes it for me are probably 3 things. System, Story and Immersion.
With System, there's been a revival of brutal hard RPG systems in Underrail, Vince games and Pathfinder. These offer more depth and I find myself kinda bored with the combat of BG3 for instance because it just doesn't have the nuance of Pathfinder. If I don't get my ass handed to me because I didn't buff with protection spells and look up the difference between invisibility and concealment, then it's like I'm playing on Easy.
Story does matter in an RPG damn it. Not just because of the interesting characters and themes you encounter but it gives you a reason to be a murder hobo and string you along.
The Immersion angle is an interesting one because it comes from two places. The first is a silent self insert character, these would be your Pathfinder, Baldur's Gate, Jade Empire sort. The game has to allow choices that are typically good or bad but it does give alot of freedom as to how you insert as a character. Wrath of Rightous for example has about 6 main paths, Angel, Azata, Aeon, Trickster, Lich and Demon. With Gold Dragon, Swam and Devil being Chapter 5 late game paths. There's something for everyone here and the choices and companions reflect that.
The second part is playing an established character. Shepard, Mike Thornton, Geralt for example. They have a personality and character arc, you're just along for the ride, controlling their actions and whispering on their shoulder. There's always going to be that wall as you control the character, because the writer wants to take them in a specific direction, so you'll never really be at a level of immersion that a silent character can allow.
I think I just described the difference between Method and Character acting.
I do have to agree with New Vegas mods missing the point of New Vegas itself though. The Mojave in NV is as much a character as the factions are but every mod like the Frontier seems to obsess over Courier 6 being the messiah like character, just like the Todd Fallouts.