Immersive Sims are real-time 3D games (usually first-person with a more-or-less unbroken first-person perspective but being in real-time 3D is the actual key bit) and always have been. RPGs can be 2D, 3D or anything in between
Emphasizing/highlighting the requirement of First-Person(FP) perspective/view.
immersive
adjective
1. (of a computer display or system) generating a three-dimensional image which appears to surround the user.
The key word for immersion is surround.
2d perspective implies top/side view. Top view is distant, opposite to being surrounded. Imagine the differences of fisher's. One is above water, on boat, a more safer position but doesn't allow more viewing detail or interaction aside what the rod/tool limit. The other submerges/immerses inside the water, more details/interaction such as with algae while danger can surround or come from all sides.
Additional these market as CRPG(primarily are tactic/strategy games) often use of multiply avatars is bad/detrimental to immersion. It distance, lessen the stakes (if one character down, there is the other, loss of character doesn't end the game) and split focus/attention/attachment.
A different form of attraction/engagement/focus more based on calculation and control of more/multiply units from what these associated with immersion provides.
First Person is required if the term/name immersion is to hold value.
An exception when First Person would not be immersive, is when its conflicts with real world experience due to the games one-eye on chest view(contrast to 2 eyes use) format/range limit or other biological conflicts/issues.
Immersive Sims can be RPGs but they don't necessarily need to have RPG mechanics at all (by which I mean stats, dice rolls, exp and numbers going up) since the actual focus is on systems-driven emergent gameplay rather than stats
One can conclude, that both aim to simulate a "reality". Computer games use stats, CRPG's use abstraction, Immersive Sim's 3d real-time allows direct use of stats as physics(or its game equivalent). CRPG format is a limit from its Table Top origin where the character's are from player projections/rules/game-mold.
Immersive Sims/Reality simulate environmental interaction, the physics as its strong point. Thief's stepping sound depending on floor. Kicking to fall damage in Dark Messiah.
RolePlayingGames simulate character interaction, the communication as its strong point.
What "Immersive Sims/Reality" seems to lack compare to RPGs is more simulation of character interaction, a more advanced communication system which require more players, a party. A party also allows/leads to a specialization/roles and dynamics/combination/interaction between them.
Would these experienced with games of Looking Glass game design, mostly agree with such conclusions?
systems-driven emergent gameplay allowing for player agency.
Would the description fit RPG's? The main/prime diffrence would be the change from player to player's.
Holy shit, you might be right. Monopoly actually is an immersive sim. What the fuck?
This further support the need for FP perspective/view as core requirement both as genre or design philosophy which seem the developer's/founder/innovators themself were ignorant of, or taken for granted based on article quotes in post #6 (
https://rpgcodex.net/forums/threads/immersive-sims.147022/post-8457934)
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Immersive Sim is deemed a faulty term/name for it can apply to, be synonyms with any good FP game for they are immersive and all games are simulating be it by abstraction or directness/imitations, one aspect or many/combined aspects.
Gameplay too is faulty term for there are alternative efficient/shorter words that could have been used instead such as "game" or "play". A reason/explanation to its existence is as a developers jargon.
Together with MOBA, that makes 3 example of poor/bad, not well thought term/categories by game developers than spread by journalist.