Seriously, look around you, pick a thing, imagine a world where the price you paid for that thing hinged on your personal individual success with that thing.
edit: to clarify, my point is why can't we pay for the model weights up front for offline models? Why would we continue paying for things we don't want/need anymore, like updates for offline software that does it's job fine?
Unless you could lease a chair and limit your cost to some finite number (which is higher then upfront cost), because chairs are easy to get by. You could also buy very cheap chairs from China for example and rent them by the hour (or that's what I heard).
The actual reason to why is -- because they can make you do it.
>What other things work like that outside of the modern tech world?
taxes
YCombinator. Unreal Engine. CryEngine. FMOD. Steam, App stores in general. Qt.
+ 90% of enterprise software that charges per seat / user.
You could argue that most of these provide ongoing services, but that will also be the case if you license one of their models commercially, contracts come with strings attached both ways.