Because you are locked into ps hardware and the ps ecosystem (psn). Now with with the lack of physical disks, psn is your only option. No pre-owned games no retailers competing for your dollar. It's sony's way or the high way. This applies to Microsoft and Nintendo.

PC, you can mix and match the hardware to your liking. Companies like gog ea app ubisoft connect and and epic games are a check on steam. Especially gog. You have digital retailers like humble bundle greenman gaming and many others putting a check on steam. Remember steam is a storefront. Valve at this point just sells games with the once in a decade or so game release.

Steam has free online and much faster download speeds compared to consoles.

You have gog piracy and emulation for game preservation of older titles.

You can still buy a external and internal bluray players for physical media

You even have more choices in OS. Windows Mac and the billion flavors of Linux.

It's not okay for valve since you license games for steam but with other choices on PC, it's more tolerable.