It's been done already. It's called
SED (Surface-conduction electron-emitter display) and was developed by Canon.
It had all the perks of CRT. Flat, very energy efficient and did not weigh a ton, but they got held up by patent troubles and LCD garb got a head start. Finding one of the 720p prototypes today would be a holy grail.
Then there's another older technology we still have today.
LPD (Laser-powered phosphor display), system functions conceptually like a CRT with lasers painting a phosphor layer instead of an electron beam and the display does not require a vacuum seal like a CRT. Because of how it works it's pretty thick, but I think many of us could see past that for an image without motion blur.
But it's not sold as a mass market product. They sell it as a 6k 225" display for corporate clients only.