Because of the technology, the way we gamble also changed. Now, it's not necessary to go to physical casinos in order to play because online gambling made it possible to still have fun wherever you are as long as you have a gadget and internet. Just like what @serjent05 mentioned, some online casinos are coming up with new feature to change what we used to and it's up to the players if they want to try this new way to gamble.
With casinos and gambling, it has happened as in other spheres of our lives: they have become digitalized. Although it is still possible to bet live, online gambling has taken market share from live gambling and is growing steadily, as people can bet 24/7 from their cell phones.
Anyhow, it's still different to gamble in physical casinos compared to playing online. If you want to socialize then nothing beats playing if you personally go to a physical casino because atmosphere and experience are quite different.
Well, although it is not the same, online casinos also have a social aspect through chat.
Talking about social aspect..
Back to History, I would guess that early forms of gambling was done socially. I mean there would not be anybody from the early ages that would play alone. That would be what a looney would do.