"is needed because touchscreen keyboards remain modestly effective and while 'Voice input is an option"
So what about
4 years old i7-2620M: VP9 1080p takes at most 40% core (=20% CPU), 2160p takes at most 150% core (=75% CPU).
https://www.youtube.com/watch?... formats 248 and 313 respectively.
No Apps => Noone buys it
Tizen runs Android apps by ACL; as I heard.