AI finds games that work across your actual age range, cuts the rules down to two minutes, and builds a rotation so nobody groans when you suggest it.
You want to actually spend the evening together, and 'let's play a game' is met with groans before you've named one.
The 5-year-old can't play what the teenager wants. One parent hates Monopoly. Somebody ends up watching rather than playing.
You buy one, play it twice, and it joins the shelf of boxes nobody opens. That's real money and real cupboard space.
Ten pages of rulebook, an argument about interpretation, and everyone's lost interest before the first turn.