

Laptops are not generally designed to run like that with a closed lid. Heat dissipation is designed around the idea the laptop is open and some of it is through the keyboard surface. The lid closed would change that.
Systems can of course be setup to power off the display but for server/service uses open laptops may not be efficient space wise.
Having said that if the scenario is low power use the heat dissipation may not be a major issue. But if there is an unremovable battery i’d still be concerned about heat dissipation with the lid closed and even just the battery itself regardless of heat dissipiation.
There is quite a range of devices out there now with varying capabilites. Things like the Onion Omega2+, Oranage Pi, and more.
Raspberry Pi also remains good. While the Pi5 is expensive and more powerful - raspberry pi also makes the Pi Zero boards which are cheaper less capable boards which are closer to what the original raspberry Pi was but newer hardware.
I’d say the Pi5 is a heading more towards a full PC like device (hence the comparisons to cost and capability minipcs pepple are making in thia thread). But there remain plenty of lower spec machines out there now similar to the original cheap Raspberry Pi concept. And we’ve had high inflation recently - to some extent the cost perception avtually reflects money being worth less than it was and buying less for $10 or $20.