I find it more concerning how the author celebrates all those hypothetical device classes, instead of focusing on being good at one thing (desktops). Feels a bit like being stuck in time loop where Windows 8 is still the hottest new thing (it never was, got ridiculed from the start). But again, I might be wrong, if there are non-desktop use cases that are not only live in production but also major contributors (perhaps something like large TV brands building on/building Plasma for their UI?), then they have made all the right calls.
off topic: feels a bit weird to read through that very talkative YouTube monologue style, that's probably contributing a lot to my perception. But, wow, so much better to have a transcript than the video itself!