Can't agree with that. Even Skyrim had a quest in main storyline (the one where we are asked to retrieve the horn of Jurgen Windcaller) that allows PC to explore the world without feeling detached from the main quest. Also, I believe that the setting plays a major role in this issue.
Fantasy-medieval settings are better in this regard e.g., though in Witcher 3 stakes seemed to be high, Geralt doing some monster hunting here and there wasn't hard to believe, the very same thing was described in the books - he had a long way to travel, he needed money along it, so it's obvious that he would stop once in a while.
In futuristic setting like in CP77 it doesn't really work, because not only you are limited to one city, there are also a lot of possible ways to transport fast around it. And additionally stating that there is some artificial time limit makes it even worse, when side content isn't compelling with stakes that high.
Let's just imagine, that cyberpsychosis quests were giving to the player with the purpose to learn more about influence of cybernetics on ones mind, which could seem to be something that could help V in his endeavors. And maybe the reward for finishing them would have been those pills that we originally get from Misty, which could serve as a way to prolong time that V has left to live. It would not only connect nicely to the main story, but also make pursuing side content meaningful in the grater scope.
