From my perspective, I strongly belive that this is a negative trend. People are missing places, they forget to enjoy moments and this is a one of the example for modern people unhappiness problem. Let me explain why I think like that.
On the one hand, people nowadays visit well-known places more often than before. Their main goal is not exploring world or learn the background of these well-known places but even for take a photograph has a positive side effect like this. On the one hand, take a photographs themselves for sharing on social media has a positive effect like this. People learn history, discover totally different cultures, meet foreign people. These are positive effects but there are some negative sides as well.
On the other hand, because of the social media craziness people loves take a photographs themselves and share it on social media. This is a modern human problem. Even my girlfriend did that in paris in front of eiffel tower. Modern human is addicted to likes on social media. These likes gives him/her an adrenaline, love of themself. They do not enjoy moment. They always thinks where should I take a photographs? Where is the best spot for my pose? When is the best time for take a photographs? Even I experienced that some people bring different clothes for take a photographs. People live for social media not for themself anymore.
In conclusion, there are some both positive and negative effects for visit well-known places for to take photographs. In my book, I stongly belive that people should search, learn, explore where they are and enjoy the moment they live and after that If they really want to take a photograph they should do it after everything. But under this circumstances, I think this is a negative effect after all.