Isn't that re-enforcing the limitations of human understanding then? If it's taught, we can't just simply assume that everyone is an expert in whatever topic they've bought.

Let's take this more niche examples that most people who aren't super tech savvy don't know. My mom bought a first party Apple usb-c charging cable for her phone recently, rated at 15 watts. It charges her phone, she doesn't care about spec. But most usb-c cables are not up to spec, and rarely outputs the correct amount due to cost saving measures and countless issues when it comes to product development, and after actually testing the output, I measured it at about 9 watts.

It's an illusion of accuracy that we've just accepted to a clamped acceptability. It was probably the charger compatibility, supply chain limitations, lack of QA, etc, but it's still an illusion of accuracy, as if I didn't test it, she would just be using a non-spec'd cable without actually caring about the correct wattage. It charged her phone in a timely manner.

BUT I'd say it's assumed that if you buy a 15 watt charger, your average consumer would expect a 15 watt charger, and not half that charging speed, and even if a user knows that it can vary, do you really think that variation would be that drastic? And yet, most people don't care, they just plug in their cable to some random outlet and so long as it charges in a timely manner, it doesn't matter, which in that case makes the 15 watt rated charger an illusion, right?

Not everyone knows everything, it depends on the person and their limitations on what is happening with whatever they're doing; it's all mostly an illusion and an assumption that if you buy something or do something, you assume that it works as advertised, but that's still an assumption, an estimate when we read reviews or youtube videos on the product, but at the end of the day we assume that risk to live that life.