I think that the thesis is more like "be warned that what you will find when going to a place you have seen promoted on Instagram won't likely be the same thing

I think that the thesis is more like "be warned that what you will find when going to a place you have seen promoted on Instagram won't likely be the same thing, because everyone else had your same idea and that place has changed in the meantime". A number or places are promoted because they are (one way or the other) "exclusive", but if they are open to the public and everyone goes there, the exclusivity soon ends. Small places like Positano did actually change due to the mass of people visiting them, on a larger scale Venice and Florence share a similar "shift". To give you a small example for Florence, once there were a number of small "trattorie" (cheap restaurants) where locals would go, eating simple, local dishes. For many years foreigners (travelers, not tourists) found these places (by mere chance), ate there, among the locals, and came home telling how pleasant was that experience to their friends, let's say 50 people, of these, maybe 5 (10%) would go in the next 5 years to Florence and eat there, so, each "positive review" brought in 1 or 2 customers the next year (replacing the one of the year before), the situation was stable. Now one "influencer" goes there and his/her experience is read by 100,000 people, of these a much smaller percentage (1%) 1000 people next year go to that place. It is a good thing (more work) for the restaurant, but - besides the queue outside - after the cook has been asked multiple times for "spaghetti bolognese" and the manager understands that the foreign customers are willing to pay 10 Euro for them (instead of the 5 Euro a first course was priced before), the restaurant will change menu and raise prices, no locals would go there anymore, additionally since very few people among the new mass of customers can actually appreciate the food, quality will lower. Soon after, the guy next door will understand that there are thousands of people looking for food (and that there is no need for the food to be good) and opens a new restaurant. In a few years "trattorie" disappear, replaced by "tourist restaurants", where thousands of people go expecting to have the same experience the original "influencer" reported. And - here is the interesting psychological aspect - either because they spent a lot of time and money to organize the trip or because they have no way (lack of culture/experience/taste) to appreciate the differences most people won't report honestly that their (unlike the original) experience was a shitty one and will as well publish photos of the place and tell everyone how nice it was, perpetuating the myth.