This level of socialization and emotion cannot be matched when you have a computer sitting in between yourself and your friends, acting as a mediator. With physicality, however, comes physical constraint. Most tabletop RPG groups have a fairly small group of players to draw from. My own groups have sunk as low as 3 or 4 players on occasion. Life is good for gamers in the Bay Area, but I suspect physical constraints make it much harder to gather together a group in less urbanized areas.
Time can also be a pretty big constraint.
Groups can only gather together when ever one actually has time, and from what I've seen that's caused the demise of many a gaming group, as high school and college turn into the real world and with it jobs and family. The combined advantages and disadvantages of physicality have produced a specific gameplay for tabletop RPGing that works very well. I'm sure we're all quite familiar with it. Play is group-oriented. Though players do have their individual stories, these stories tend to be subservient to or intertwined with the overall group story.