But at some point the virtual Venice will be better than the real thing: the temperature will never exceed what you find comfortable even if your travel companions have different preferences; there will never be too many tourists; your hotel room is more luxurious than anything you could hope for in real life; somehow you always find what you were looking for even when you read the map wrong. You always get a seat at your favorite restaurant. The buildings are cleaner. The "flaws" are just at the appropriate level to make you feel it's authentic.
More importantly, virtual plain-old Venice will have to compete with virtual Space Venice, where canals float between islands floating in space, or Renaissance Venice, or Black Death Venice for the horror fans, or Vegas-style Venice, or Godzilla-attack Venice, or Lego Venice, or any number of crazy variations.
Places like Venice are also important to us now because it stands out so much. But to people growing up with higher and higher quality virtual environments it will seem more and more boring and bland when compared to modern re-interpretations.
To put it another way: "My" Superman movie was the first Christopher Reeve one. It's the "authentic" one. I measure the new Superman actors against that one. I measure new Zod's against that one. But it was not first Superman movie, and I haven't even seen the older ones. And to many in my sons generation, it's some old movie that's far too slow-moving that most of them have not seen or heard of.
To take another example: The painting Scream, that to some already is "that painting that looks a bit like the Scream mask".
To generations growing up with virtual Venice 2100 with taller, more impressive buildings, more dramatic bridges, and other "upgrades", real Venice may soon enough become "that boring city that looks a bit like virtual Venice 2100 but isn't as nice".
The way both video gaming and social media have exploded as cultural forces makes me think inauthenticity won't be a problem for the majority at some point. Many people already seem more than happy to judge themselves by their friend counts, Instagram likes, and go on voyages and have experiences online rather than meet up in real life.
I personally think simulated Venice could well be better than the real thing for most, as long as the real world remains relatively expensive, dangerous, and uncomfortable (compared to sitting in your house). There will always be people who prefer real experiences, but I think that group will continue to shrink.