Green is a difficult color.
Also there is this legacy of not having optimum CRT phosphor material for green. So the green phosphor used in CRTs produce yellowish kind of green, which does not perfectly map to the human vision system, and greatly limits the gamut; basically if pure grass green color is needed, one has to mix some blue, but then you have less saturated color because of the unwanted yellow tint mixing with the compensating blue, resulting in addition of white.
The sRGB color space is also compromised by this legacy limitation, even if no CRTs are used anymore. Even AdobeRGB is; look up the usual gamut picture and the green end corner is way too much on the right, and not in the middle.
Red is a tad too yellowish, too, but it's not as bad as the green, and red can be rationalized by efficiency at least. Deeper wavelength (say 660nm) would allow wider gamut, but look much dimmer because of human eye response is weaker there.
Blue phosphors were excellent from the wavelength perspective. Light output (efficiency) and lifetime sucked, though.
Now with LCD screens etc., which use dyes, this does not matter. LEDs have their own limitations, but high-intensity green LEDs do not have that yellowish tint problem; it's actually the opposite, they are a tad too much on the blue side, by having the peak at 530nm instead of 540, if my memory serves right.