Doom3r: Well, if Witcher 1-3, Fallout 3 & 4 and Mass Effect games are RPGs then what makes this game not one?
Tormentfan: But this isn't like those games, this plays like GTA.. drive around, get jobs, shoot people, take objective.. that kind of gameplay isn't in any of those games you mentioned.
Do you think GTA is an RPG?
I have no idea. Long time ago I tried one of GTAs b/c everyone was buzzing about it and I could not get through the game b/c I did not feel it my game so I abandoned it and never looked back at the franchise. So if you are going to say "GTA this and GTA that" it has no meaning to me, b/c I have almost no knowledge about it.
However let's talk about the games I mentioned. Also since you completely omitted any notion of the CP main story we are going to omit main story of the other games I mentioned. Also let's not talk about the DLCs since CP has none yet and saying something like "well in W3 there is a whole not related quest line in Toussaint is unfair since it is a huge DLC":
Witcher series: take a contract from the notice board, talk to somebody, might need to use Witcher Vision for some investigation, slay the monster (even worse with Witcher 1 where you needed to collect so many fangs, heads, brains)
Mass Effect: you get some message, fly into the star system, land on the planet, enter the one of the 2 or 3 copy-pasted hideouts and deal with the enemies (most time shoot them), loot the locker.
Mass Effect 2 - 3: talk to somebody, land somewhere, shoot everyone, use interrupt or red/blue line to get somebody's loyalty.
MEA: let's not talk about this one.
Fallout 3: this one had really fun and interesting sidequests, however it had dumb quests like "collect so many nuka cola quantum bottles"
Fallout 4: this one is the worst since I do not remember almost anything outside of the main story (which was "Meh..." at best) and "so and so is attacking a settlement" (which was a chore), finished that game once and would like to pretend it never existed.
However if you would look at the main story then F3, F4, ME, ME2, ME3 are pretty linear.
F3 & F4 are very linear, many times worse then CP2077.
ME: the only choice that mattered within the game (not franchise, since there is only one CP for now) is are you going to take onboard Wrex and Garrus or not. If not you would not take them then you cannot deploy with them. Also you can kill Wrex on Virmire and the only difference is going to be is that you cannot deploy him further. IMHO way worse than in CP since you can choose your destiny here.
ME2: the only choices that you make within the game are the choices related to the loyalty, when you are going to land on the trapped ripper and whether you are going to retaliate immediately or complete all unfinished business. You have similar thing happening in CP: for different end result you need to win few people and Johnny. What CP does even better is that you have 4 different final missions instead of only one.
ME3: stupid "traffic light" resolution plagiarized from the original Deus Ex, except to get really "good" ending you had not only to make right choices on primary missions but also grind multiplayer (which was pretty fun at the time though however b/c I tried quite a few builds and promoted my characters so much there is no way for me to get a "bad" ending which sucks). Before a "Director's Cut" DLC was a total trainwreck and a big FY to everyone who cared about the story in the game.
Witcher: err... 2 choices? Small difference between choosing Flaming Rose vs Squirrels vs no one and who do you romance Shani or Triss. Don't really remember anything else.
Witcher 2: this one has the most impact out of all games: what path are you going to choose in the end of the Act 1 would create a completely different game for you. However beyond that choice you are on the rails from start to finish.
Witcher 3: most of the game is on the rails. You've got to choose few things here and there to affect the epilogue you are going to get (Was it about 15 minutes of the play time? However it is quite emotional, when I've got my ending I thought I've go the worst, up until I bought the sword that had 0 damage and 0 weight).
With all this said I personally would say that the game as a standalone game without DLCs are on the same level as each of other mentioned games with the exception that it has a lot of "activities" that are not important except if you want to oneshot any enemy you are going to see on the final mission.