Got a lot of questions on how I spin up linux VM's so quickly

Explanation is pretty straight forward.

Linux was built in the 90s. Hardware improved more than a 1000x. Linux virtual machine startup times stayed relatively the same.

Turns out we kept adding junk to the linux kernel + bootup operations.

So all I did was cut and remove unnecessary parts until it still worked. This ended up also getting boot up times to under 1s.

Big part of it was systemd btw.

So, if I use a "16 vCPUs, 32GB RAM, 400GB SSD" machine for a period of intense compute, and then want to scale that down to "2 vCPUs, 4GB RAM", most of my storage disappears?

That rather ruins the potential of the advertised scalability.