Would Vampire the Masquerade be a better game if you could just drive between setpieces in a fully rendered city instead of having a loading screen? Probably, but it would also increase the development workload by an order of magnitude for what would effectively be a gimmick that wouldn't really add a lot to the game.
And even outside of RPGs, there are countless adventure and FPS games without vehicles. Doom doesn't have cars, neither does Tomb Raider, Devil May Cry or Resident Evil.
Of course if you're thinking of something like "GTA V, but you can't drive cars" then obviously that seems very tedious, but if you build the game with this constraint in mind it shouldn't be much of an issue. Then you can focus on other aspects of the game.
Cyberpunk is clearly not at its best when you're in a vehicle, and there's no telling what else they could've implemented and finished if they had cut it entirely and focused on other aspects of the game instead.
The reason why it's tedious is because the map is built around cars. You can't go very far without encountering a road. This makes it fairly hostile to be a pedestrian since you're relegated to walking on sidewalks (or in front of traffic if you're daring).
A city built around pedestrians could have a much different environment, like open green spaces, cobblestone paths, proactive NPCs engaging in little dialogues with shopkeepers, people trying to sell you stuff on the streets, etc. A real "night out on the city" vibe that I don't think any city-style game has tried going for yet.