Except that many games are not tied any specially to Steam. What makes them sell is the small price for limited amount of time (and good exposure for that deal), just like it works for HIB. This has nothing with piracy, just pure business. Also AAA titles are often overpriced, or they’re just not that much worth for the individual (like I would buy most AAA games for 5E only, otherwise it’s not worth to me, because even when some are good enough to entertain me, it’s nothing great, though I don’t mind waiting few years for price to fall).
Steam games are pirated, or activated on accounts used solely for that game and then shared or exchanged.
This works well, though there are exceptions for very popular games. Look at Counter Strike scene, the pirated one is so strong it’s total alternative to the official one, they do ‘official’ leagues and clan matches within it.
Not that easy when it’s done as dedicated servers so anyone can run them. Privately, or with some web of trust for bigger community.