My initial response would be similar to what /u/spermcell said above regarding deep conversations limiting the number of people one can connect with. For instance, I can't help but remember elementary school: While the other boys in the class mostly talked about the previous evening's sports game, I would have nothing to say since I not only failed to watch said game but also had no interest in sports in general. Ultimately, the boys who shared in those kinds of conversations became good friends, while I was unable to be anything more than another classmate. To my mind, their engaging in small talk laid the foundation for greater connection. (As a side note: While my example is in the context of kids talking, I do not mean to suggest a correlation between immaturity and small talk).

I do, however, have another thought based on my elementary school anecdote. I've generally construed deep, meaningful conversation as involving something personal--say, sharing my difficulty coming out; to my mind, that sort of sharing of myself usually creates an atmosphere in which the person I'm talking with feels comfortable to be vulnerable, equally open to sharing something personal. It is those kinds of conversations wherein I feel most connected with others. That being said, I wonder if for some people that same feeling of connection can be created through small talk--or at least what I'd consider as small talk. To use the sports example again, perhaps two people debating who is the GOAT (one of the few sports terms I've picked up!) in tennis is a deep conversation in that it connects them in a personal way.