For CPU clock, I agree the gains are marginal, yet BIOS settings still allow the end user to trivially further bump up the clock. There are young people with a

For CPU clock, I agree the gains are marginal, yet BIOS settings still allow the end user to trivially further bump up the clock. There are young people with a lot of time on their hands who will do it for that 3% uplift. Further, with memory we have things like XMP which again are blessed by the vendors and are 100% within the definition of overclocking. Just because a memory module can run at XMP rates doesn't mean the motherboard or the CPU have the signal integrity or power integrity margins to support the timings. And this is something component vendors can't optimize from the factory (only system vendors can), because it depends on multiple parts. In the old days one couldn't enter BIOS setup and find even a single mention of overclocking, and the term itself was taboo because it meant operating the system outside the design spec. Nowadays a lot of vendors use OC in marketing. I think this alone makes my point about being mainstream.