>>4114864It has better dynamic range (so he can underexpose and fix it later), less noise, and better autofocus. "weighs twice as much" but we're talking less than an extra pound unless he wants to get into wide angle zooms and telephoto/supertelephoto lenses. And then you know something? APSC is still impractically HUGE. I would never never carry a fuji xt-whatever with a xf50-140mm f2.8 anywhere I wouldn't take a full frame camera, even a DSLR.
It is really a negligible difference, in size/weight/cost, not as negligible for image quality with stills, but the fuji does slightly better video and looks much better as a fashion accessory. I believe fuji has better IBIS by the X-T4. but sony's less great IBIS is still a thousand times better than the X-T3 lacking it entirely.
I recommend everyone start with FF because it's at the intersection of cheap and available and unless you are highly specialized from the outset into superzooms or wide angle landscape shots, not an impediment to having one with you. If they still can't afford that then I recommend they start with micro four thirds because it is actually cheap, and actually small, unlike APS-C.