It's kind of my only one. I have an iMac that is probably from about 2010. It still works and is basically there as a media server and for use with maybe ripping BDs or editing some video. I use it so little that I've replaced the since-deceased Apple wireless keyboard and mouse with cheap ones.
Since I bought that computer, I have purchased a MacBook Air (in 2014), MacBook Pro (last year) and MacBook Pro (this year cuz someone stole that previous one). The MacBook Pro may have been expensive as hell back in 2010 when my previous one basically died, and I didn't need portability that much. I think 2010 me was stupid for thinking that.
I know that some people need a desktop. I just don't know many, if any. I told my parents to make their next computers notebooks because then I can more easily fix them (it's usually a software thing or they don't know how to use it thing). Same deal with when a computer needs a trip to an Apple Store.
In my opinion, if you don't need an expensive iMac/iMac Pro or Mac Pro, you likely don't need a desktop. Get an external monitor. With AirPlay, you might be able to just use your TV.