> It must be nice to have enough space at home to dedicate some to a server room (servers are noisy btw). But many people live in small apartments in a city and so don't have that luxury.

Absolute bullocks.

For most people running a home server, a Raspberry Pi is plenty and is about the size of a deck of cards, maybe two decks if you want extra storage and use an external storage device.

If you need something beefier, you can probably just use an old laptop, or maybe a full second PC under your desk if you need more. You could easily fit a Threadripper or Xeon system with 128 GB of RAM, multiple drives, and a GPU or even two in a single ATX PC case.

If you need a full server rack, you're an extreme outlier beyond even 99% of homelab creators.