I dont understand people who work on a tiny 15” screen when they can have multiple large monitors. Yes, you can use externals with your laptop but then you need to invest in a squid (commonly called dock?) that will link your stuff to the laptop. And disconnect/reconnect your stuff when you go away.
Also let’s not forget the full size keyboard. I suppose that’s why no code coding initiatives come out once in a while, those people can’t stand typing on their laptop :)
My solution is one serious desktop with everything and one mid range laptop that I can work on if needed, but avoid like the plague.