Yes Cameraderie, I can see your point, I have not sailed the world (as yet). Initially I used my mobile phone as a modem. I don't use WIFI for Internet, but the G-3 mobile network to log on. Sofar I never left the shores of Australia for more than 70 miles. Only between towns/harbours I am out of range.
And yes, often I looked at laptops, as they take even less room and use less power than SFF computers. And every time I upgraded, I decided on a desktop,...sofar.
Apart from price, the deciding factor was nearly always, that I can fix desktops, replace parts easlily and add things economically. However in truth I never updated my computer parts. Just replaced the lot after 3 or 4 years.
I must say I have never owned a laptop. I guess, one could call me biased.
PS I have WIFI on board, connecting my with my printer, phone etc.