I'm not convinced that it has universal penetration though. In casual use most people are not going to bat an eyelash if Skryim is called a cRPG.
Fair. Especially my last lines are a very personal (and quickly-created) definition.
I feel that calling Skyrim a cRPG makes the category of cRPG too broad, no longer describing unique gameplay and game design aspects. Undertale, Pokemon, DOSII, BG1&2, Disco Elysium, Outer Worlds, Fallout, Skyrim, World of Warcraft, Diablo, and Final Fantasy are all rpgs. But I wouldn't necessarily recommend Undertale to someone who loved Outer Worlds, or BG1&2 to someone who loved Skyrim. For me, Skyrim's gameplay is just too different from that of DOSII and/or BG to fall under the same sub-genre.
So I suppose the question is: If you knew a "casual" person who loved Skyrim but didn't like most other types of video games, which of the following would you recommend? BG1&2, DOSII, Fallout, and/or Outer Worlds?
That would depend entirely on the person. However, I don't actually know anybody who is both "casual" and "likes Skyrim" so it is difficult to asses.
In any case, this is quite a derail of the thread. I'm not particularly invested in the question of whether Skyrim is a cRPG, so I am willing to backpedal on that.
Full disclosure, I asked some IRL friends about the "Skyrim as cRPG" thing, and they said I was nuts. Ironically they used a completely different argument than you (which was that a cRPG requires tactical elements). None of them are "casuals" though. They also derided the idea that DOS2 was the only mainstream cRPG of the decade, mostly because they didn't think it was "mainstream" (these are people that liked DOS2).
In any case, my original objection was to the idea that "DOS2 was the only mainstream cRPG of the decade." I think there are better arguments to be made against that claim that don't involve classifying Skrym. Specifically, that there were other games that definitely qualify as cRPG that sold in the same ballpark as DOS2.
Pillars of Eternity 1 and Pathfinder: Kingmaker were both in the same order of magnitude as DOS2 saleswise. Its not clear to me how you define mainstream if NOT by sales?
