I've seen things going the opposite way. It's only recently that an average person could jump on eBay and get assembled low-level electronic module/boards for cheap, and assemble into their project.
Yes, you'll probably have difficulty walking into a STORE to buy PC components, but only because online shopping has been killing local shops for decades now. You'll find it easy to get that stuff online, for better prices.
PCs, since the very start, have been going through a process of being ever more integrated each generation. Not too many people install sound cards, IDE controllers, etc., anymore. CPUs, GPUs, and RAM are about the only holdouts not integrated on the motherboard these days. It's possible that could change, if CPUs and GPUs becomes fast enough for 99% of people, and RAM gets cheap enough that manufacturers can put more on-board than 99% of people will need. And while you might not be happy about that kind of integration, it comes with big price reductions that help everyone. But we're not there yet, and I can't say how long down the road that might be.