They’re fanless and low-power, which was the primary draw to going this route. I run a Kubernetes cluster on them, including a few personal websites (Nginx+Python+Django), PostgreSQL, Sonarr, Calibre, SSH (occasionally) and every once in a while, an OpenArena server :-)
Actually, as a web guy, I find the ARM architecture to be more than sufficient. Most of the stuff I build is memory heavy and CPU light, so the Pi is great for this stuff.