At 75C most overclockers are thinking... "yeah, I'm done now". But that's on a stress test, Games should run about 10C lower so, yes 75C is high for gaming. Depending on where you are, if you in my temperate zone, it as like 21F out today.... summer temps get into the 90s. Indoor temps might be 68F in winter, and 78F in summer here, but not everyone uses AC.... so it's not unusual to see a 30F (17C) temp swing seasonally. Even with 86F, that 18F swing means CPU is 10C hotter.
Been building PCs for almost 25 years now and at this point, I'm comfy as long as I don't hit 80 on any cores. Peeps w/ a bit more nerve into competitive overclocking will go 85 but outside the DICE / LN2 crowd, folks generally won't go higher... but again...