I don’t see any reason to use a Raspi instead of an used thin client for selfhosting.
They use about the same energy, but the Mini-PC has x86, which has better software support, has more ports, and runs more stable.
I have a RPI for my 3D-printer (Octoprint), and I will soon replace it with a “proper” PC, because it always crashes.
Raspberry Pis are good for very small appliances, but for anything more, they suck imo