Don't lose faith for the reason that Nikon is capable of bringing out excellent lenses at great prices. On the contrary, I think congratulations are in order.
I think it is a good sign. Lens designs progress and better lenses become available at lower prices. It would be backwards imho, if they deliberately hampered the optical quality of slower lenses to make them perform badly just because they can produce them more economically. That would be machiavellian.
I am a junkie for fast primes and I have accumulated a small collection: 24/1.4G, 28/1.4D, 35/1.4 AIS, 35/1.4G, 50/1.2 AIS, 50/1.4G, 58/1.4G, 85/1.4D, 105/1.8 AIS, 135/2D, 200/2VRII, 300/2.8VR and 400/2.8VR. In addition to those I now also have the Sigma 24/1.4 Art, 35/1.4 Art and the older 50/1.4 HSM.
They all have a different character and I don't feel at all that they are redundant. Not even the triplet of 50 mm lenses. I will probably next get the Nikkor 20/1.8G and the new Sigma 20/1.4 Art.
Enjoy your lens and accept the fact that tomorrow will bring new cameras and new lenses. Or trade your 24/1.4G for the 24/1.8G if you feel that the new one is better suited to your shooting. I know I'll keep mine.