Comparing Amsterdam's controlled conditions and professional growers to Australia's clandestine conditions and possibly rookie growers (amongst other variables) sets a pretty high benchmark, but fair enough. I think we do well considering.
After several generations of inbreeding, authentic: Yes. Seedbank quality: No (depending on the reputability of the seedbank of course).
That's another thing. Immature bud from rushed harvesting, or overly ripened bud from potentially greedy growers can make for some less than impressive product.
I grew some really poor stuff from a few stray seeds found in an ounce of excellent Sour Diesel. I've also produced magnificent weed from piss-poor shiva skunk that was full of bag seeds (the original grower obviously hadn't removed the male plants).
I'd say 80% is pretty good weed that I'm extremely grateful for. 10% is like holy fucking fuck amazing. 9% is nothing special and the remainder is stuff that is so special, no combination of technique, seed origin or any other factor could ever replicate it's brilliance.
Remove all these variables and I'll bet the White Rhino and Blue Cheese definitely live up to their cannabis cup winning reputations.
TL;DR: Sometimes being sold proper strains sets expectations a bit higher than I've actually got from smoking them, but they're still far from bad - just no different than the rest of what's available. Weed in Australia is pretty good IMO, and has been getting even better in the past few years.