Gambling is becoming popular because people have no global purpose in life. 

In the 19th century, people believed in endless scientific and technological progress.  However, the First World War showed that technological progress can serve not only the cause of good, but also of evil. 

In the 20th century, people have a new global goal - space exploration.  However, by the beginning of the 20th century, space exploration projects were curtailed.

Instead, the Internet and the virtual space began to develop.  However, the internet is just chatter.  People are disappointed. 

Therefore, they began to actively seek excitement and drive in gambling.