Part of what made it jarring was that most of the pregens weren’t young hobbits.
Paladin Took and Esmeralda Took are young: underage and just out of their tweenage years. Both of them are explicitly described as looking for adventure.
Drogo Baggins and Primula Brandybuck are older. They are in their forties and currently engaged to be married. Drogo’s write-up is pretty ambiguous about why he’s involved (beyond Bilbo being his cousin) and Primula’s explicitly states she’s there to make sure the younger hobbits don’t get into trouble.
Lobelia Bracegirdle is even older. In the books, she’s a spiteful and greedy minor antagonist. Her character sheet suggests that this remains the case in this adventure. It’s pretty unclear why she would be involved with Bilbo (except to suck up to him to gain part of the inheritance).
Rorimac Brandybuck is almost 60. He is married, has 3 children, and will shortly become Master of Brandy Hall. None of his children appear in the adventure, and no real explanation is given why he is spending time hanging out with his son’s future wife rather than what would normally keep a married man with 3 children busy in a pre-industrial society.
The first adventure is Bilbo telling us that he wanted to buy a map from other hobbits but they refused. He wants the map because he thinks that he can decipher the inscriptions to go on an ADVENTURE! He wants us to break into their house and steal it. When we arrive, we realize that the house is actually a local museum.
Bilbo comes off really poorly from the exchange, particularly since he is explicitly sending other people to do his dirty work. It isn’t realistic for Drogo, Primula, Lobelia or Rorimac to go along with this, and even Paladin and Esmeralda should have serious reservations.
Bilbo also insisted on coming with us in the 2nd adventure, which really undermined the idea that “he’s pushing younger hobbits to live a little before settling down”.