Most of the everyday user experience, in my opinion, is based on short bursts of performance.
Load tab, start menu, wait a few seconds for the realtime AV etc.
They are not continuous loads.
Also, the whole idea of eg games (as opposed to eg video editing) is that you are ‘large’ in terms of CPU, and therefore nowhere near 100%. After all, if you were to sit just below that limit, you would not be able to absorb the outliers, and you would still have frame drops at the most unfavorable moments.
In addition, that 1.5kg will (hopefully) take a few seconds to warm up completely.
And that those short turbo moments will in theory not be long enough to kick it to throttling so quickly. Something with heat capacity.
In practice, therefore, you will only want to put a fan on such a passive block if you plan not to upgrade your CPU (mobo memory) for as long as possible (>4 years) while the games become heavier over time and the Approaching 70-100%. In that case, make sure in that last year that you have some more case flow or that you put a fan on it; that’s just part of it.
And then with that next CPU upgrade, you can take that fan off for a few years, so to speak. Because Noctua always arranges super long compatibility for new sockets. Are they known for, afaik.
I myself have a motherboard where I can link my good silent front and back case fans in the BIOS to the CPU temperature in such a mild way that I still don’t use them at all during desktop and mild game use (older games). hear. (note: not all mobos have this)
During a continuous load you will hear your case fans a bit more, but I wonder how that compares to the “one less fan” phenomenon.