The MBP was owned by my former employer. Perhaps I might have bought it, but I didn’t feel like spending money on a 2013 MBP in 2019 
That said, I had (and still have) a 2015 Air which I use as a travel machine, and I might have used that one in combination with a desktop. I did consider such idea, but decided against it for a few reasons.
First, my desk is in the living room, and I want to avoid taking up more space here. I keep the laptop on a stand, so I can put stuff underneath it, so it takes up zero space. In addition, the laptop provides me with a second screen so I don’t need a second monitor, which further reduces the space clutter (and expenses!).
Secondly, I like the convenience of using a portable machine for work and personal stuff. I have this one all-rounder which works for all my needs. When I need to work outside of home (which happens fairly regularly), I just take the laptop with me, and everything works as expected.
Finally, I was considering some option of setting up a home server I could ssh into, and run stuff from there. I guess my main problem with this is the support for working outside of home. I could setup some VPN, but this would require a stable and a reasonably fast internet connection, and I’m still not sure if the lag would be acceptable. Another possible drawback are GUI apps (e.g. observer or developing gui apps with scenic), although admittedly I don’t really develop GUI apps at all, and observer could be used via distributed Erlang, so maybe that’s not a big problem.
That said, this is an interesting idea and I’ll consider it again the next time I need to upgrade.
