The bigger issue tends to be from the emulator itself taking shortcuts to run without emulating every single transistor and circuit of the entire system.Displaying legacy interlaced signals correctly*, without lag?With the exception of light guns, I have a hard time coming up with a single thing that CRTs are superior to flat panels at.
(* without the use of an additional external scaler)
There's the basic appeal of the shadowmasked rastered image too, not so much a benefit over modern TVs, more a desirable trait for the full retro experience.
And I see no reason why we should exclude external scalers from the equation.