Thank you.
From an administrative standpoint, especially if we're talking about defined contribution plans, people who contribute to small plans can't get fees as competitive as those associated with larger plans.
Furthermore, participants in defined contribution plans generally do not have to decide on their own investments. That aspect is managed by experts who are devoted to that. Expected returns are thus greater than those that individuals who make their own investments can achieve. In that respect, it has been proven that there is a significant gap of approximately 2% per year between the returns of professional investments and those of personal investments.