This is absolutely true, and I'll take it even a step further: great people can still form dysfunctional teams even if they all do good individual work.
Often times in an early stage startup the problem is the team doesn't gel enough to adequately explore the problem space. In those cases, the founder might conclude that the opportunity wasn't there, but maybe it's because people weren't aligned enough to push far enough in the right direction. It's impossible to know whether there was really a viable business there, or whether it was a failure of the team. But subjectively after going through several startups and other early stage projects, I know the feeling of a team that is gelling, and it can make an unquantifiably huge difference to early results.
Often times in an early stage startup the problem is the team doesn't gel enough to adequately explore the problem space. In those cases, the founder might conclude that the opportunity wasn't there, but maybe it's because people weren't aligned enough to push far enough in the right direction. It's impossible to know whether there was really a viable business there, or whether it was a failure of the team. But subjectively after going through several startups and other early stage projects, I know the feeling of a team that is gelling, and it can make an unquantifiably huge difference to early results.