What is described in the OP is only one reason for me why not to expect to get everything from one single source. To me, that would be unrealistic and actually even unfairly demanding. You can build a support network and find things that fill different areas of your interests and needs. It's also safer because if one does not go well for some reason, it won't collapse the whole universe. I actually don't even like my therapists to try to get to everything about me and my life even if it is tempting on both sides at times.