But even in your examples you are quoting your experience, which a lot of people aren’t going to have. Most people wouldn’t know how much RAM they need for a Windows machine with 2 monitors, using your example, and they don’t know who to ask to find out. I don’t think you are wrong in your assessment, I think a lot of people, maybe a majority, don’t honestly know so they buy the most expensive version that they can and specifically in Apples case they then complain about how expensive an Apple computer is, when they would have been perfectly happy with one costing less. The same thing does happen with Wintel computers, just not as frequently anymore. You can buy them at Best Buy or Target or Walmart and pay somewhere around $800 and get an ok amount of memory and an ok processor and at least for a year or three the computer won’t seem slow. But they aren’t usually doing anything extravagant with it. But is an iMac Studio supposed to be more or less powerful than an iMac Pro? How would a new customer know? M1, M1 Pro, M1 Max, M1 Ultra, Apple has a history of blurring performance categories with their naming.
In an age where tech is one of the most important thing in our lives, I think most people know what RAM is and how much they need. And if they don't, there are plenty of resources to find out, including Macrumors:
https://www.macrumors.com/guide/16gb-vs-32gb-macbook-pro/
https://forums.macrumors.com/threads/mac-mini-m1-ram-advide-8gb-vs-16gb.2334242/
If someone still doesn't know what they need, I think that price and availability are pretty good indicators. I agree that most people will buy what they can afford but I disagree that they will get the top spec. Is the average user going to spend $4K+ on a new computer? I don't think so... There's a very small group of people that are going to buy that spec. Like you said, they're going to Best Buy or Costco and picking up something off the shelf and that's usually a lower or mid spec at best, meaning retailers already know what the most popular model is likely to be and that's what they'll carry to increase sell-through.