"i'm a bit conflicted about this manga. In way, what she is doing is positive to him, making him go out of his shell, faking until you make it and all that.... But I wonder if it is worth it to do things you actually don't want to, say things you actually don't believe in and act like someone you aren't just to please a group of people that otherwise wouldn't even know you exist. People that really matter to you would accept you as you are, I wouldn't like to live in a farse."
That's true, and in extremes it would be unhealthy to constantly follow the flow just to fit in.
However, it's also very useful life advice. Being able to navigate and accommodate other people's interests to make something work for a group (or in your favor) is a very useful skill. It's really relatively rare that the people you're with are going to either have the same interests or ignore our bad habits, like close friends, or family. Say if my coworkers want to go to a dive bar, I'm not just going to say "ew, that place is disgusting." That might make me look like a prude in their eyes and it'll be harder to work with them. Either I suggest somewhere else to go for the night, or I come up with some excuse to go do something else some other time. Learning which option will work in that scenario is part of 'reading the room' as mentioned in the chapter. If everyone has already decided on the dive bar, I give up an excuse to leave and say that we should check out insert_establishment_here instead on friday, since I can't change their minds on going right now. Alternatively, I head off the discussion before everyone decides to go to the dive bar, and steer them in the direction of somewhere quieter/less sleezy/has a better beer selection.