I see your point! Let me elaborate what I meant by "need" because I wasnt clear. My bad...
In fact there is not an actual need for monitoring anything about a system unless something is not doing what its supposed to do and trying to find the culprit. Most of us using HWiNFO and all tools alike, just to view system info, to try to understand it or whatever anyone has in its mind. Temps, voltages, % usages, % rates, actual rates and all the good stuff a tool like HWiNFO provides... No need. We do it because we like it and because we can. I can fully understand the view of a temp, a delta value, a voltage, ram usage, data rates etc... Things that changing during system workloads (light or heavy). I do it.
There is a reason (I believe) why HWiNFO sensors do not display drive/storage usage. Its not something that changes on the fly or even for a day or days unless you install something. Maybe if you're having a large dynamic page file and load an app that it is using it a lot, but then again you have the actual page file usage. I have a large page file but it is static. There is also all the junk that it is written on the OS drive but it is rather small and requires days to start making a significant change on drive space.
So... what I was really asking and trying to understand, just for the sake of conversation and the exchange of ideas:
Is there an actual point of monitoring drive usage? Does it have a purpose? Or you want a real time value just because you want to see it all times even if its not changing at all?