$ tar -xzf ubuntu.tar.gz && chroot ubuntu
    tar (child): ubuntu.tar.gz: Cannot open: No such file or directory
    tar (child): Error is not recoverable: exiting now
    tar: Child returned status 2

if I have to do wget of something (and find the url to wget) it's not worth it

I would use debootstrap.

https://semjonov.de/posts/2021-09/minimal-ubuntu-installatio...

If it requires to read a whole blog article like this to setup someone can make and sell a product with a one-liner command that does it. They could call it, idk, decker or something

I take it you don't remember learning Docker? I had to read way more than one article to fully understand it. I also had to learn what cgroups were and all kinds of things.

    tar -zf ubuntu.tar.gz
    tar: Must specify one of -c, -r, -t, -u, -x

Doesn't work on my shiny macbook. I'll stick with Docker, I guess.