Nah nah I disagree. My i7 8700k old PC server runs around 60 watts with 4 hard disks and ~30 running containers. It’s a large machine so that I can easily expand with more drives but I can easily buy a smaller mobo on the used market if I wanted something smaller. Depending on how old your NAS is, and what you are doing with it, PC may be more power efficient.

I was able to use it to write some selfhosted flask applications in python. I’m not a programmer but it did give me a good head start.