That desktop motherboard and CPU likely requires more power, more cooling, and a bigger case.

I can see the "Framework motherboard as SBC" idea catch on for everything from set-top boxes (Steam Machines could make a comeback this way) to a poor man's blade server.

Laptop processors make sense when space is at a premium, even if it's not a mobile device. But if space isn't an issue, desktop parts are usually a better choice; you can usually power limit desktop cpus to laptop levels if power usage or heat are a constraint.

Being able to just buy something that works when you get it is a big plus IMO.

I’ve tried a few times in the last year and finding parts (that are actually available) for a sub- $500 small-form-factor system seems to be beyond my capabilities :)

"the average Core i5-1135G7 in our database is just as fast as the Core i5-10400H, Core i5-8300H, and Ryzen 7 3700U in multi-core benchmarks. The CPU acts even nicer when under single-core load, reaching similar heights as the Ryzen 7 5600X and Core i7-8700K."

https://www.notebookcheck.net/Intel-Core-i5-1135G7-Processor...

It's better for SBC. Also laptop iGPU is better than desktop.