I've done the shared flat thing on four continents. Had a blast every time.
I guess it depends on the stage of your life, and what sort of process you go through to choose your flatmates, but I feel like the shared flat thing was a rite of passage for many of my generation. Really can't empathise with the naysayers here, but maybe it was just luck of the draw.
I have lived alone and also with different roommates since moving here (a few times with one roommate and another time with two). For the most part, it seems you will be paying about the same as for a tiny studio but you will actually have a kitchen and living room.
There are a lot of upsides. More space, a kitchen, people to talk to, other people to help clean or talk to the landlord/handyman if there is a problem. In general I am a fan of it.
On the other hand, it really depends on the people you are living with. I have heard stories of not so great roommates. Not paying rent, slobs, loud at night, etc.
So far I have only lived with people with whom I had mutual friends, so I could trust that they would be decent people and I could ask my friends if they think we would be a good fit. Because that is a big consideration. Not all of your friends would make good roommates. You need to make sure that you have similar habits and standards when it comes to how you want to live.
I usually ask people if they are willing to do chores themselves (when adding a roommate once we even showed them our chore chart). For me, having a clean house is very important, and I also want to do it myself and not pay a cleaner. Some roommates agree to split the cost of a cleaner, and that’s fine for them. It’s also good to have similar ideas of having people over. If they want people over multiple times a week but you are a more quiet, private person, it might not work. Are you guys going to share food? Do you have opposite schedules? That could be ok, but if one of you is a super light sleeper it could be trouble. Got to figure out if you are compatible in those areas.
All that said, there are also benefits to living alone. You can do what you want (play music at midnight, decide to not mop the floor for a week, have people over anytime you want with no worries). So there is more freedom. So just need to decide what you want.