I use RPi and some old laptops and some old PCs to run my nodes. All have their good side and bad side.

RPi: Good: Small, cheap, a lot of support, very low power use. Bad: Can be slow for IBD, and even as cheap as they are, you can get used laptops / PCs for free.

Laptop (assuming used): Good: Built in screen, lower power then a desktop, can be had for very little. Bad: For the most part NOT designed for 24/7/365 operations, and you have no idea how the previous owner(s) treated it. Could have been dropped, left in a hot car cooking over the summer or freezing in the winter. And so on.

Desktop: Good: Cheap (or free) and everywhere. Going to faster then the laptop / RPi for the most part. Bad: Pulls the most power, although not as bad as a laptop you don't know how the previous owner(s) treated it, would need a screen to do a lot of the initial setup.

There is no one size fits all. Something like this that I am selling still works well ( I have a couple still running) https://bitcointalk.org/index.php?topic=5471664
BUT, you have to then hunt down a m.2 sata and deal with the fan issue........

-Dave