I think the only gen where I have not owned every console is the GCN gen. Outside of that I always buy all the consoles so that I can play any game whenever I want.

Is it practical? Probably not. I use my Xbone so much my PS4 Pro practically collects dust and I only use my Switch for Civ in bed. I can see people being content with one console. All of them offer enough to keep anyone busy.