a) all-in-one is often a compromise, e.g. people might like a a relatively plain Linux or BSD to do routing - best on "boring" hardware, but you don't get the b

a) all-in-one is often a compromise, e.g. people might like a a relatively plain Linux or BSD to do routing - best on "boring" hardware, but you don't get the best WiFi performance on such hardware. Whereas APs/integrated routers don't necessarily run such OSes best, have driver issues for newest standards etc. b) incoming internet connection is often in a corner somewhere. Best position for an AP is elsewhere. If that's a problem depends on how you get internet and what the place looks like.