In his early years, Buffett charged investment fees through a partnership.* But when he took over Berkshire, all other investors in Berkshire went along for the ride without paying anything for Buffett’s skills. Surely, Buffett could instead have run an investment management business for 55 years charging 2% + 20% like so many other funds. If assets under management grew too big, he could just have stopped taking in more capital. Why did he make that choice? *Averaged 62% gains investing his personal money from 1951-57, starting with less than $10,000, and saw average gains of 24.3% for a partnership managed from 1957-69.
He has quipped that he regrets not continuing as a partnership. But I think he knows that he couldn't have done what he did in a partnership format. Under his current situation, he can have significant drawdowns and no one can do anything other than sell their stock. His "AUM" is unaffected. There are no such things as redemptions. This works really well for a strategy where an investment can take several years before paying off.
Finally, the audience realized that Buffett is an excellent manager, and as an investor - a complete zero! Initially, he had a great team that did an excellent job of investing. But Buffett does not know how to value the people he works with and has lost his best staff; Those with whom he worked for a long time were not satisfied with his investments, and, of course, people are leaving him. His eloquence in these cases is powerless!