If I always use my laptop with an external keyboard and display, why do I need to carry these around with me? They largely determine the form factor of the PC. A suitably robust box, housing CPU and storage, could be much smaller and do the job just as effectively. Does anyone sell such a device?
These are small, but I don't see them specifically marketed as portable - i.e. robust enough to withstand the sort of treatment a laptop is expected to withstand.
Any bump severe enough to significantly damage a micro PC would also be enough to crack the screen or otherwise damage a laptop too.
Shock resistant, dustproof, etc. industrial computer modules do exist but you'd be paying something like 10x the price of an ordinary computer so it's not worthwhile.
Because not many people carry a PC, monitor, keyboard, etc. around. We have laptops for that. You can get a sturdy case like a Pelikan if you want to protect it.
https://www.cnx-software.com/2023/07/22/khadas-mind-raptor-l...