There's a reason other than "because it's fun to tinker." I do it because I love the capabilities it provides. I don't love managing Ceph & Proxmox & whatnot, but I love being able to deploy whatever I want into a beefy cluster with 10gb without having to worry about cloudspend. If I wanted to replicate what I run in my home infra (I don't consider it a lab), it'd cost 200-300 in compute and easily another 300 in storage a month. Instead I spent ~2k on hardware and ~35/month in electricity.

It's the same thing with 3d printers, some like them because they want to install clipper and tune the best/fastest benchy. I do it because they love being able to CAD something and have it in my hands as soon as possible.

That said, nobody goes as far as this guy without really enjoying the tinkering