No, G just means that it has no physical aperture ring. Really, the Nikon equiv of "L" is lenses that have a gold ring on them. Sort of. Lenses with the gold ring are likely to have weather sealing and such.
Nikon is much less stingy with things in some ways, though. Like, the 50mm 1.8G has a rubber weather sealing gasket on the mount (though it isn't advertised as weather sealed) and has fast auto focus with full time manual and a nice build. Comes with a hood, etc. Compare to the Canon 50mm 1.8. Lol. Yeah.
They can skimp on things compared to Canon, too, though. An example would be the 24 1.4G. Fantastic optics. Super pricey, great lens. However, the AF motor on it is a micro-USM type motor (like in Canon's 50mm 1.4 and 70-300 IS USM). Many other expensive Nikkor lenses have micro-USM type motors instead of "ring USM" type motors (obviously not called USM by Nikkor--but SWM). Another example of this is the 24-120mm VR. I think this also uses a micro-USM type motor. Wheras on Canon 24-105 you get a real ring motor.
You win some you lose some, just depends. Cheaper AF-D (older lenses, with an aperture dial), from the 90's, say, are often built really, really, well, too.