...but without money to spare. If the desktop fits his needs there is nothing gained in replacing it with a proprietary and form-factor limited device like an Apple laptop unless he's hog-tied to the Apple world - which does not seem to be the case here.
I use a bunch of devices, some portable, some not. When I need something portable I take, let's say, a T42p running Linux. I'm typing this from a resurrected iMac 27" running Linux which sits next to a Compaq 6910p in a docking station connected to a 24" monitor. The iMac is the newest device at 12 years, that T42p is 17 years old yet it still works fine for most things as long as I can reach the server-under-the-stairs. Sure, that M1 makes for faster media consumption but... that is not what I use these things for. I also foresee a not-so-distant future where that M1 lies in a cupboard due to some malfunction - bad battery being the most likely - which is deemed too expensive to repair while most of those old devices around here still continue to work.