If you don't understand how the parts work, what they do, how delicate the connectors are... Without any experience you can't know what not to do. Trying to build a PC, a lot can go wrong if you don't know what you're doing. That a lot of expensive parts that can be destroyed in a blink of an eye if you make a mistake.

You say all the parts fit only one way. Well, that depends on how clumsy or ignorant the builder is. Or both

Rocket appliances.

Plus it would probably heavily limit your hardware choices unless all hardware vendors jump in. If not a lot do so, you might as well just stick to prefabs.

Personally I don't see the benefit. PC building really is already simple enough. It's just people's mentality that keeps them back. You really have to something dumb to break anything except maybe with some CPU socket designs So if they would fix that last pain point we are already there basically.

I'll be honest, even though it's not hard, it's still intimidating to the average person. Having easier connecters with clear slot labels would be an absolute win for everyone. But then it introduces the problem of having another competing standard.

The only way they could make a PC more modular without making more proprietary is to use laptop expansion ports or USB C expansion ports.

I can tell you without a doubt the average 12 year old is most likely unable to even install windows...they don't know how to use computers anymore like people born in the 80s early 90s learned to use and fix them.

I have built at least three machines, and I hate it. My hands tend to shake, and I worry when I drop a screw into the motherboard or trying to figure out how to wind a wire into position without causing damage. I am not a rich man, and fear losing money or my data if I mess up.

Honestly, I dislike your position, it sounds like a humble brag.

No, a PC ecosystem where all the parts are shrouded and there are no wires to futz with.

It isn't unrealistic - the original Starfox and Yoshi's Island games were on cartridges, which included 3D acceleration (Super FX) hardware that increased the performance over the standard SNES. For the player to use it, all they had to do was just insert the cart into the SNES and start playing. The Nintendo 64 also had RAM expansion Paks that plugged into the machine, doubling the RAM to a massive 8 megabytes, in less than 10 seconds.