Can a N100-class minipc” be installed inside of a wall with a touchscreen and serve as a PoE powered Home Assistant interface? Can it be used to build a portable battery powered smartphone like PC (Compute Module 5)?
Raspberry Pi’s biggest strength is its form factor and low power draw.
To drive a touchscreen and serve as a Home Assistant interface you need neither a Pi nor an N100-class mini PC. That's the job of an ESP32. 20 bucks... for a pack of 5.
(plus the screen. And ethernet / PoE variants are rare, and not as cheap, so if that's a hard requirement, maybe not for your specific use case)
I might also point out that with Pi/mini PC pricing being the way it is, a used iPad mini mounted to the wall is also in the same price range. As a bonus you could remove it from the wall and walk around with it, and you’ve got way less DIY work to deal with.
If I tried to put a mini PC where my Pi currently sits - a very narrow shelf - it would fall off and probably hurt itself. You can put a Pi just about anywhere.
Raspberry Pi’s biggest strength is its form factor and low power draw.