My Ubuntu for mobile devices post-mortem analysis
Cross-post of what I wrote on /r/linux:I definitely think Canonical bit off more than they could chew:    Mir
    Not making use of existing Android drivers (I think they resolved this issue later on)
    Building their own app deployment and isolation system (Snappy)
    Building their own browser (although they did wisely reuse CEF, or was it WebEngine?)
    Convergence

I really wanted Ubuntu Touch to succeed, I even backed the Ubuntu Edge when it was first announced.However, I think Jolla/SailfishOS did a number of things better:    They used Wayland.
    They used existing Android drivers (using libhybris).
    App installation/deployment is done using regular RPM. There's currently extremely minimal app isolation. This is a very hard problem. Let the Flatpak folk solve it, then adopt it.
    They used Nokia's browser (based on Gecko) and office suite (based on Calligra). These were used on the N9, which had a larger install base than all existing Linux-on-the-mobile projects.
    They used a well-tested ConnMan/ofono combo (these were used on the N9, see above).