[userbinator]

I assume that CRT technology development stopped decades ago, but could we have e.g., replaced the heavy glass with some plastic-like material to save weight without compromising the picture?

Metal-cone CRTs were common in the early decades, and had a flatter screen than typical all-glass construction; here's the largest of those, a 30":

https://www.earlytelevision.org/dumont_30bp4.html

a TV using it cost almost $1800 in 1952 (equivalent to over $21k today):

https://www.earlytelevision.org/dumont_ra-119.html

I think metal-cone CRTs became unpopular due to the glass-to-metal seal not being as reliable, and difficulties with insulation (the whole cone is at the final accelerating voltage.)