The soft-play area was heaven for him, and he liked flicking through the donald-duck comic books.
Even now, when he's nine, I go every month or two with him for an afternoon. He has no shortage of books at home, but he gets to run around, look at books, and play with other kids. He enjoys himself enormously.
I will say it’s very very common for folks to use the library for its primary purpose of renting books - which of course requires a visit twice in a month - once to collect and once to return.