Isn't this going to be variable, depending on what people put in it? Since it's open air, which isn't really aimed at quiet computing, and this case doesn't include any fans, I can't understand how this would be helpful.
Not in ways that matter. The majority of all builds are very similar. Even so, this is why you standardize your test setup.
But, in the grand scheme, if case A gets lower temps and noise than case B when you put a 9900K and a 280 CLC in it with a 1080ti, then Case A will still get lower temps than case B if you swap all that hardware out for a 2700X, NH-D15 and Vega 64.
The temps themselves will be different. The RELATIVE PERFORMANCE of the cases will still show the same trends. There is very little hardware you could install that would create an anomaly here, and such hardware would be something users are already accounting for as "different" to a more normal setup.
Gamers nexus does a great job of testing this, including often modifying cases, fan placements etc to give a broader understanding of the way each case works and could even be improved.
EDIT: as for noise, while in theory you could have a test system that produced a lot of one type of noise that one particular case, by fluke, dampened well despite being shit at other frequencies, in practice this is extremely unlikely to happen, as PCs mainly produce broadband noise from fans, and high frequency from coil whine. There's enough going on at all frequencies to ignore the possibility of the sound being "targeted" by unscrupulous case designers like a VW emissions test.
Noise testing is admittedly harder to do well. It is not difficult to do the bare minimum though - it literally requires one quiet room and a cheap decibel meter.
