The origin of the modern day RPG is the fantasy role playing games of the past - the original white box of D&D, and all of the other clones or forks that came about from it. The existence of these games occurred at a cross-over point with the tech community, leading to the birth of computer games meant to emulate these sorts of games in a single-player format. This was, after all, the only model at the time.
CRPGs developed in this manner, transferring the raw numbers and stats from these games into a format the computer could work with using only some light RNG. JRPGs developed in term off of these CRPGs, and as a result, tend to remain crunchy even to this day. This leads to a major problem:
CRPGs Fail as RPGs
Role-playing games were meant to allow you go into a game and have a fantasy adventure. They were not meant to be about tactics and resource management - all of that was stuff that got tacked on later, because it was part of the CRPGs, which took that from older games because it was the only thing they could. Establishing a stronghold and managing domains? Having complex social interactions? Researching spells with unique effects? Swinging from chandeliers? These are all things that are almost impossible to replicate outside of the table-top.
On the reverse side to this, you see the narrativist counter, which has taken more hold nowadays. Take a game like DA:I, that has a small CRPG-like shell around it, but is really just about telling a really bad story. This is not an RPG either, as games of this sort rarely give the player a true degree of freedom. Not to mention that most of these game writers are absolute shit, and thus shouldn't be allowed to do this sort of thing to begin with.
This is why Elder Scrolls games sell so well.
From Arena onward, TES games have marketed themselves on putting (You) in the role that you can do shit. You can explore, collect items, make things, make spells, and all of that shit. Daggerfall did a lot of things, and later games have done less - but made up for it by providing modding kit, since they understand their player-base will just make what they want for themselves. It's the same shit as house-ruling in table-top games.
The games don't have to be good, they just have to be the only ones that are doing what they do. Other companies have started trying to do the same shit with this push for open-world games, but have been failing, for one simple reason - it's not about an open-world. It's about being able to feel like you're immersed in it.
Perhaps the best attempt at coming close to what a computer RPG, as modeling the original RPGs, should look like, is Dragon's Dogma. It let you fight great monsters, but also mow down casual shit; it let you do all sorts of cool things, craft items, climb walls, and otherwise truly get into things. But it had a few weak-points - the limited dialogue, very loose story, and the underlying JRPG mechanics ("why the fuck can't I hurt this bandit?" "he's too high level") all bite it on the ass. Not to mention that it didn't have an established fan-base at the time of release.
To another degree is WoW, which at the time managed to come very close to this. It was, like a TES game, not very good. But the huge world and community, combined with ease of access relative to old MMOs, led to it leaving a huge mark. It is also worth nothing that older MMOs promised this sort of thing as well, but often (as with WoW) were unable to deliver an authentic experience, because too many different players had different views of how things should work.
RPGs are not, as a rule, good games. The "great" RPGs like Baldur's Gate and the like are crappy off-shoots of the tabletop games, and simply do not hold up as games. What a good RPG would look like is not hard to imagine: a hypothetical hybrid of Morrowind and Dragon's Dogma, taking the best aspects of each, and providing a game that will truly revolutionize the genre.
The first company that manages to produce this will become rich.