Will CRTs ever come back as flat screen technology ?
First, they did have flat screen CRTs. In fact, in the end, virtually all CRTs "screens" were flat. But the monitors themselves where not "flat panels" because the "guns" have to be set back away from the inner surface so the distance the light from the guns has to travel, and the intensity of the beam hitting the screen are about the same whether hitting the center of the screen or the corners. So CRT monitors are nearly as deep as they are tall.
It should be noted that CRT monitors are like vinyl records. They are analog - not digital - and the actual image quality, like the sound of analog vinyl, is still preferred by many. I note there is a reemergence of vinyl lately which I for one, am happy about.
They can certainly make a super high resolution and fast (sorta) CRT monitor. But I don't think CRTs will return. Remember, CRT stands for "cathode ray
tube". And the problem with electron (or vacuum) tubes is they are very heavy, HUGE, require a lot of energy and are still very energy
inefficient (they emit a lot of heat - which is wasted energy).
The larger the screen on a CRT, the thicker and stronger the glass "envelope" of the tube must be to support the necessary vacuum pressures inside (actually the pressures are pushing in from the outside). That's why the biggest CRT screen made for consumers was just 45 inches and it weighed over 500 pounds! The required depth meant the cabinet would not fit through many standard doorways in many homes!
Plus, they are dangerous. If the CRT monitor's tube breaks, the vacuum creates a huge implosion. All the glass shards go crashing into the center, then are expelled out in many directions. While this happening is actually much less common than stories led us to believe, it did happen. So not good. Also, there are many 1000s (20,000 to 25,000!) of volts applied to the anode of the CRT. Getting your hands on that will certainly get your attention. While stories of death were pretty exaggerated too, it did happen - though it was probably with someone who already had a bad heart, or perhaps a pacemaker. More likely is the recoil action caused the person's arm to slam into the wall, breaking or cutting their arm.
I said "sorta" when it came to being fast. LCD displays have pixels made up of transistor/diodes that are turned on, then turned off as need. This ability to turn them off is critical.
CRTs use red, green and blue light guns to "light up" the phosphors in each pixel. Those pixels are NOT turned off, they simply fade (decay) and stop glowing. While they decay quick, it still takes time. To maintain a color, the guns "refresh" the phosphors (light them up again). But that decay rate is much slower on a CRT than a LCD's ability to turn off a pixel. That's a problem with fast moving objects on the screen - especially with games.
So, no. CRTs will never come back.