On History, there's a self-filmed TV show about 10 survivalist dropped off separately on Vancouver Island competing for $0.5M to be the last standing. The show is fantastic, not for the impressive survival skills, but for the human psychology. The show is called "Alone," and I'm fairly certain they (re)named the show after filming. What you witness over the course of just weeks, is nearly every wilderness expert abruptly losing their will to go on because there is nobody to share it with. They openly acknowledge that they have what it takes to continue, and were originally okay with being away from their family indefinitely, but they all just completely lose their desire and interest in winning or continuing because they are so alone.
In short, isolation doesn't just make it more difficult for you to achieve your goals, it rips the desire to achieve them from your psyche altogether! This is empirically shown and self evident in numerous aspects of society: solitary confinement being classified as torture, team dynamics, mentors, pair bonding, tribalism, etc... It's also why YC (mostly) doesn't accept solo-founders, as well as many other respected VCs.