Except knowledge.

It's foolish of you to assume that most people want to build a computer.

And before people respond with 'its just Legos'

There is so much more to it for someone with little to no knowledge.

Bios and firmware updates that require certain CPUs coupled with certain motherboards.

CPU sockets and inter compatibility.

The different specs of any given component and the value they provide to someone looking for specific workflows

Sizing of components and cases

Knowing where to find parts and what prices are acceptable.

Etc, etc ,etc.

Pick something that you know nothing about, let's say cars just as an example.

Now imagine, let's, say want to buy a car but it doesn't come with wheels, you don't get a list of 4 wheels to choose from, You get, lug patterns, sizing, and type, offset, wheel diameter, wheel width, bead lockers or no bead lockers, 1 piece, 2 piece or 3 piece, etc.

Now you have to spend all this time researching just about wheels, and then how they fit with the car you chose specifically earlier in the process, it would be frustrating and incredibly difficult for people who just want a car.

Go on any thread or forum and ask 'what GPU should I get' which is already making assumptions about someones understanding and knowledge (that they even know what a GPU is), and you will get 20 conflicting answers and need to write a paragraph in responses to narrow it down enough.

Present someone with no knowledge this: 'DDR3-2666 CL9' vs 'DDR3-2000 CL7'. How do you really expect someone who just wants to play a video game to just implicitly know what those numbers mean, how they relate to each other etc.

Building a computer is an immensely difficult task for someone who doesn't know much or anything about it, and believe it or not, the reality is not everyone wants to learn, places like lemmy and other tech focused echo chambers seem to forget that.