Fortunately not all programs are so solitary, but I’m guessing that is the norm. My D interviewed at several tippy top grad programs (incl. in the Ancient Eight) and noticed how some really were: you are own your own from practically day 1. Perhaps Harvard is the most solo of them all, at least in her Dept. Moreover, while she loved her visit to Columbia, the solo nature of their work and perceived less advising turned her off.
Fortunately, she received an offer of a team-oriented program which fit her style better. That being said, the team results in a different workload as one HAS to attend Lab meeting, give feedback and participate on other’s research along with her own.