You can absolutely buy genuine parts for recent iPhones: https://selfservicerepair.com/order (that website looks random, but it's actually Apple's official self repair supplier)
Yes, the System Configuration step is still required to pair many of those parts. This has been discussed ad nauseum. Perspectives vary between it being a necessary security precaution and an entirely self-interested move by Apple to control their supply chain. I suspect the truth is somewhere in between.
I've never done the System Configuration step, but it requires chatting with a support agent and it sounds much easier than the repairs themselves. I absolutely agree things could still improve. But I also think we should recognize this new iPhone 14 re-design as a huge improvement that shows a promising trend.