I would like to ask about variety, i think all the genres you mentioned are also present in all wrpg. Medieval Fantasy: lots. Cyberpunk: Deus Ex and Cyberpunk. Steampunk: Arcanum (underrated game btw). School Drama is a jrpg specialty lol where else you will get the waifu baits
. Post apocalyptic: Fallout is king of this imo. And you have games like Wasteland 2 and 3. Space games like Mass Effect, Vampire the Masquerade is also something new, it uses similar engine to Valve and the concept is cool. And Disco Elysium is kinda visual novel type of detective but its still rpg due to its stats check. Kingdom Come is another one which is more about religious and realism. Yakuza is JRPG specific though but its just a modern japan setting.
I dont know, maybe i didnt play all the jrpgs out there but i definitely dont see them having advantage in vareity, in fact it feels they are the ones lacking variety, especially in modern era, its mostly sequels and remakes. Final Fantasy, Persona, Dragon Quest and Pokemon are the dominating ones. Suikoden 2 is my favorite but those are the old ones. Chrono Trigger, and Xenogears/Xenosaga. How much variety is actually there?
Many of the most unique CRPG titles are niche unfortunately so there are a lot more variety in JRPGs. No one bats an eye when a JRPG is steampunk but it would be a big deal if Bioware or Bethesda announces one. Morrowind is celebrated as the most unique Elder Scrolls, as it should, but if it was an JRPG everyone would think it as business as usual.
More examples of JRPG originality:
There is a JRPG where you play as two Italian brothers who were eaten by a huge turtle and you explore his organs. Another one you play only as the shorter brother but everything is made of paper!
The most profitable JRPG of all time has an idyllic setting where everything , including economy and wars revolves around cute monsters which are captured by kids with the purpose of to be the best there is I guess.
In Valkyre Profile you play as a Valkyre recruiting dead people for the battle in the end of times.
In Megaman Battle Network you play as a kid and his self-conscious internet avatar where you hunt bugs and criminals in the net.
Eternal Sonata setting is the deathbed dream of pianist and composer Frédéric Chopin.
The World Ends with You has the Japanese Shibuya district in Tokyo as the setting but in the limbo. You use magical pins.
In Earthbound you play as a bunch of kids battling zombies, aliens, robots and even cars, on an americana style setting.
Shadow Hearts setting is a crazy version of our world in the XX century.
JRPG experiment more within the genre also. Cyberpunk is Cyberpunk 100%. JRPG on another hand mix many elements of various genres. FFVII is modern fantasy with steampunk, cyberpunk and medieval fantasy elements. FFVIII is modern fantasy, school drama, sci fi with some medieval fantasy here and there. STM: Strange Journey is an amalgamation of military, religion, The Thing movie and modern fantasy.
I wish CRPGs deviates more from the usual stuff. CRPGs would benefit even more from it than JRPGs since one of its strong point of CRPGs is the interaction with the setting/NPCs/story. It is a joy to interact with the colorful people and locations of Planescape Torment.
The JRPG genre have its own wild west franchise but CRPG don't! Such a wasted opportunity!