I've done two "stage one" builds of Gentoo. I'm not super skilled but, I had a lot of time and reference material. My bet is that folks could but would not want to. There is significant time cost.
Also, I'm still using one of those original builds on my laptop - upgraded of course...still mad love for my daily driver.
It's a pretty automated process. I'd estimate 1/10 of all people who can use a computer and install software at all could do it if they wanted to and had sufficient time.
Also, I'm still using one of those original builds on my laptop - upgraded of course...still mad love for my daily driver.