Yep, this was my home lab circa 2005 (above). Five pcs on the floor, all single-thread AMD Athalon, and four gigs of ram. I was running MTGO YaTBoT trading MTGO Cards, one bot per PC. I took this lab apart long ago, and mom and Dad were probably happy to have this mess out of the house.
When I bought my first house, I wanted a real lab. Ok, I just wanted a plex server for my media. I was tired of relying solely on my main computer for all my lab experiments so I built a dual Xeon 32 thread 64 Gig server. I bought a four-post rack and added a PoE switch. The switch allowed me to use Ubiquiti Cameras and WiFi access points around the house. The server allowed for plex and a host of other services.
I crammed everything into a small enclosed rack and stored it at my MIL’s house while we looked for a home and lived in our RV.
We moved to our new house two years ago, and I added a couple more servers. I upgraded the switch to Ubiquiti and added a UDM Pro. While we had a couple of Unifi cameras at our first house, we are approaching double digits at our current home. At some point, I will explain what each server does and how I use them.