Documenting every apple variety in North America

I grew up near an orchard containing just over 120 varieties of apples and remember being very impressed that so many varieties exist and yet we end up eating only a few of them. Now reading that someone compiled an apple-o-pedia of more than 16k varieties just blows my mind!

People in the South East of England who love apples could do worse than visit the Brogdale Collection in Kent. They have over 2,200 varieties of apple and do orchard tours as well as an annual apple festival: https://www.brogdalecollections.org/the-fruit-collection/

For the welltodo apple aficionado this must be a treasure to have in the library. For me, it is the kind of resource I wish was available on-line, preferably with retained aesthetics. As far as I can see it is only available as (a considerable number of) books.

I only skimmed the article, but it's always been my understanding that apple trees are extreme heterozygotes and that a seed from any given apple can produce a wholly new varietal.