> Consumer PCs and laptops spend most of their time idle
Not when Windows gets its grubby mitts on them. I will frequently hear the fans spin up on my Win10 laptop when it should be doing nothing, only to find the Windows Telemetry process or the Search Indexer using an entire fucking CPU core.
Idle power usage is what matters.
The 15 seconds it takes to launch Discord and install updates isn't going to be driving the overall efficiency of your PC.