That's stilll way high, at least for some anchor types.
Going through the West Marine catalog, I get the following anchor weights for a 24'
boat:
8, 6, 9, 4, 6, 8.5, 5 pounds for Danforth type anchors (p 706-707)
18, 33, 10, 30, 16.5, 14, 25, 16.5 for plow type anchors (p 708-709)
West has an incentive to sell you a bigger anchor, not smaller (more profit),
so if anything, these numbers will be on the high side.
I'll stick with my 5 pound Danforth. I can usually anchor in sand where
it just burries itself. The harder it blows, the deeper it goes. And it
snags rocks pretty well too.