Steam do the same pseudo-ownership crap Sony have just been lambasted for. The cart page explicitly says 'purchase' but you have no right to sell, trade or lend them. Steam only reluctantly added refunds due to legal obligations and if you have a justified reason for a refund outside of the 2 hour/2 week window, you have to communicate with Google-esque customer service.
Years before Half Life: Alyx, Valve said they would never make single player games again. It made sense - TF2 was making silly money selling silly cosmetics. Presumably, the economics have now changed to make single-player viable again: any further player-base goodwill means a few more years of getting away with predatory BS.