118 C is otherworldly. Early 2000s AMD chips are going “Whoa, dude, relax”.
I have no experience in microprocessor engineering and done little research on the topic, but I’ll leave these here:
Basically, there are a lot of factors. Additionally the designated operating limits aren’t pushing against the physical failure threshold per se, rather are primarily performance reliability, stability, and efficiency limits.
In other words, Apple’s design and selected materials can, in their determination, tolerate five to ten degrees celsius higher operating temperatures than comparable microprocessors.
Some topic related examples:
When enthusiasts overclock GPUs and the VRAM operating temperature exceeds the manufacturer’s/designer’s set limit, often there’s graphical artifacting. Are the components at imminent failure? In most instances, evidently not, as the problem is correctable/recoverable. However, it is a point where the output is blatantly unacceptable (i.e., significant amount of errors). Also on this subject, OCs that are supposedly “stable” in gaming are nowhere near tolerable for far more sensitive (i.e., accuracy) workloads like data science (e.g., folding@home).
The internal space of automobiles has reportedly reached ~50ºC. That’s an ambient temperature typically more than twice what most people allow in their homes. With the electronics heating during normal operation, I’d be comfortable in assuming the microprocessors in the
ECU, audio head unit (i.e., “stereo”), and other components often press against and probably exceed 100ºC operating temperatures. And I’m also confident assuming they’re similar or even less efficient designs than a desktop computer system.
With that said… If you want to put effort, whether that’s system adjustments (e.g., fan control override), physical adjustments (e.g., placement and orientation of your Mac), or something else, to maintain operating temperature at a more optimal level, that’s fine. Although, I do recommend a “PC” for that enthusiasm.
However, let’s not ridiculously try to mix, merge, or exchange desirable with necessary.
Your Mac is extremely unlikely to melt, catch fire, breath fire, stop functioning, glow red, etc if the processing cores are at 120ºC/240ºF.