While there have been plenty of solid three-cost land destruction spells over the years (and almost entirely in the nineties), Sinkhole was the only really good one for two-mana
Theres going to be a Final Fantasy set, for example
So far, sales have actually been lower than they were this time last year, but with fewer listings on the marketplace, the card has spiked anyway
Plus, milling our opponent is pretty pointless because we can mill infinite cards if we manage to assemble the combo, so milling a few earlier doesn't really matter, and we have no other mill cards if we don't assemble the combo, so winning with mill is basically off the table
Illustrated by Steve Luke Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Not Legal Brawl Not Legal Legacy Legal Comp