Only AMD can really say whether Vega turns out to be a failure or not. We don't know what their goals or constraints were. In the end, if it has a performance/price advantage over Nvidia's (year-old) offerings, then it will be at least a relative "success" from a consumer pov.
It seems to be bringing some technological advancement too - using GPU memory as a cache seems like the way forward. Naive calculation gives me a couple of MB to store a single 1080x1920 texture. Current game usage is approx 1000 times that. It takes more than one texture to build a scene, but there seem to be gains if more textures are loaded on-demand (or slightly earlier).
It seems to be bringing some technological advancement too - using GPU memory as a cache seems like the way forward. Naive calculation gives me a couple of MB to store a single 1080x1920 texture. Current game usage is approx 1000 times that. It takes more than one texture to build a scene, but there seem to be gains if more textures are loaded on-demand (or slightly earlier).