Unity: We have to charge for every install because we only see totals. Also Unity: We can tell which install is which, so you won’t be overcharged.
That’s probably pretty negligible numbers. In fact I’d suspect that the number of people who buy a single copy that they then install on multiple devices is lower than the number of people who buy a game and never play it.
It’s also much simpler to implement and the numbers are verifiable. Unless… that’s exactly what Unity wants; just “trust me bro this is the correct number” kind of deal.
People eventually upgrade their computers. Swapping out mainboards and/or reinstalling Windows probably counts as a new device.
Right, but how many people keep games for that long? How often do they reinstall? It’s tiny numbers. Even if it’s 1 in 100 installs that’s a tiny extra cost compared to the rest. In reality it will probably be much lower, and - again - most games have at least about 30% unplayed ratio.