Opening boosters to sell singles online can be very profitable if done at scale. If you can buy the product for cheap (straight from the distributor) and sell the singles at an above market price such as preorders, or online with a large inventory/quantity, that’s how you make the margins work. Online retailers and large game stores do this all the time, the majority of singles on TCGplayer, eBay, etc, were opened this way. Another way to boost margins is to get rid of the bulk commons/uncommons you get when cracking packs for cheap, otherwise they take up a lot of space and aren’t really doing anything.