My hot take is that this is practically irrelevant for the vast majority of desktop users, even hobbyists. Unless you have an absolute rats’ nest of cables inside the case or you are overclocking the chip close to its thermal limits, your chip should run just fine with a small form factor heatsink/fan, which an older, non-enthusiast case should have no problem fitting. As one data point, I’m cooling my CPU with a Noctua NH-D15 inside my Antec Three Hundred. A somewhat tight fit? Maybe, but certainly no performance issues.
My hot take is that this is practically irrelevant for the vast majority of desktop users, even hobbyists. Unless you have an absolute rats’ nest of cables inside the case or you are overclocking the chip close to its thermal limits, your chip should run just fine with a small form factor heatsink/fan, which an older, non-enthusiast case should have no problem fitting. As one data point, I’m cooling my CPU with a Noctua NH-D15 inside my Antec Three Hundred. A somewhat tight fit? Maybe, but certainly no performance issues.
The emphasis was on newer, the latest Intel CPUs can run absurdly hot under load.