I personally really liked Unity, and I was following Unity8 development for a long time so I'm genuinely disappointed to see it go - partly because I really tho

I personally really liked Unity, and I was following Unity8 development for a long time so I'm genuinely disappointed to see it go - partly because I really thought it could shape up to something really cool and partly because as you say, the convergence dream is basically dead, as is any realistic future of Ubuntu on touch devices. I know Gnome has for ages built features with some theoretical touch device in mind, but only Canonical/Ubuntu has ever shipped remotely viable touch based hardware.