I missed it recently when wanting to compare government revenue and expenditure for several countries. Without it, I didn't bother as I'd have to look figures up manually through each respective country's own budget website, and ensure figures were like-for-like (which they rarely are), and doing this for each country each with its own conventions is prohibitively tedious. Therein lies the value of Factbook; all that miserable distillation work was done for us.
The rationale for defunding was 'why should the US tax-payer fund something that's equally valuable for everyone in the world'. I think that's fair. But I lament its removal and wish the US could rattle the tin so other countries chip in and bring it back.