I can think of a lot of examples, both simple and convoluted, that are by no means unambiguous (to me, at least). There's a lot of steps, and permutations thereof, between what was classically considered an end-user's discrete hardware device and services like GFN that utilize an interactive video stream sent from a datacenter. The only concept that seems unambiguous to me would be something akin to 1 nontransferable license = 1 concurrent human user. Other than that you're getting into the technical weeds because pretty much everything to do with computers involves abstraction layers of hardware and software, copying/reading/accessing/transferring of data, and any component, or even part of a component, can exist anywhere and involve countless third parties despite the content never being actually utilized by anyone other than the licensed user.
I suspect the only thing that needs to happen to resolve this is for Valve, Epic, etc to change their publishing terms with IP holders such that they agree to have their content accessed on any hardware, singular or plural, local or remote, so long as it's only operated by the 1 licensed user. If need be, they can adjust the revenue split accordingly to encourage any holdouts. The larger established studios are obviously another matter, but that kind of goes with the territory right now.
I suspect the only thing that needs to happen to resolve this is for Valve, Epic, etc to change their publishing terms with IP holders such that they agree to have their content accessed on any hardware, singular or plural, local or remote, so long as it's only operated by the 1 licensed user. If need be, they can adjust the revenue split accordingly to encourage any holdouts. The larger established studios are obviously another matter, but that kind of goes with the territory right now.