The kids' reaction makes perfect sense to me and I grew up with an encyclopedia set in the house.
My family was poor so we couldn't afford the "nice" encyclopedia sets like Encyclopaedia Britannica. Instead, my mom bought the Funk & Wagnalls encyclopedia one-letter-at-a-time from the grocery store. E.g., the grocery store didn't have the entire A-to-Z set at the store. What happened was volume 'A' would be in the aisle near the checkout. You add that one book to your grocery chart. (One book wouldn't blow the whole household budget.) A few weeks later, the volume 'B' would appear. After a few months, you'd eventually end up with entire A to Z set. F&W was the "more affordable" encyclopedia and they brilliantly set up a "installment payment plan" by tapping into mom's weekly shopping habits. Very clever strategy to use supermarkets as the sales channel instead of commissioned door-to-door salesmen. But even that was too much money for us and my mom couldn't afford the entire set in one year. So the volumes she missed had to wait until next year with a new print edition which was a different color. So our encyclopedia set was a Frankenstein set combining different years. A lot of older HN readers will know what I'm talking about.
I used that F&W extensively in school but I don't wish I had another set of books in the house. Today's Wikipedia is much better. It covers thousands of other niche subjects that a limited set like F&W could ever possibly include. And extensive hyperlinks to see how topic-X-leads-to-topic-Y.