I think PC gaming has been growing in popularity, i dont see that being overtaken by mobile anytime soon, as i dont see mobile being competitive with desktop GPUs anytime soon (let alone RAM, cpu, cooling, power availability, etc)

Also, with the growing trend of 'cord-cutting' i think more and more people are hooking their laptops up to their TVs and watching netflix and youtube that way. Though the trend in that space seems to be pointing more toward curated ecosystems like roku, apple tv, etc.

But i think eventually for pretty much anything else the hardware and software will reach a point where you can dock your phone into some cradle and that will be your desktop environment also - this has been tried and failed many times, but its usually because the performance just isnt there to be competitive with real computers.