Originally posted by Sanquin:

I feel like the amount needed was set so high just to be a time sink. As, especially for iron and up, you spend a LOT of time traveling to get that much to your base. Not to mention the collecting and smelting you have to do as well.

Tbh I've found swamps with around 40 crypts, sometimes up to 50. And most swamps in any seed regularly have ~15-20 crypts. If you don't find an abundance of crypts after 2-3h of gameplay I think you have a bugged seed