But its all under 1 roof and can be taken from you in a fire or be stolen?

I mean it could also get dropped yea, sure. This is just a neutral discussion of the costs, I'm not making an argument for anything.

(As for data, the third hard disk isn't actually bought yet and is meant to represent an offsite backup. I might use something like AWS Glacier or Hetzner Storage Box for this anyways cuz this is mostly for experimentation. I just like the idea of having a homelab.)