Sure, not necessarily, but that’s why I said very likely, rather than leaving it as “they are”. Qualifiers.
Yes, there is a subset of people that build very expensive rigs that don’t know or care about anything other than putting it together, but at least from my experience, while putting together a computer isn’t actually that hard now, most people simply don’t do it for a variety of reasons (including they know how but don’t want to put in even that much effort or time).
And if were talking about those that are willing to throw down $500 for the processor alone, on top of the money for a 1080 Ti, but think “eh, screw it on the heatsink” or aren’t willing to take any time to see if there is a good way to configure their system that’s already known or ask for help, that sub-set is likely no longer ‘normal’.
I wasn’t talking about just the tweaking side of things here, I was talking about things like “don’t set game mode on 2700X”, and “use something better than stock cooling”. Again, I’m talking about enough knowledge for “decent” performance, not “fully optimized”.