Why would using real-time settlements have helped combat some of the chaos that occurred during the January 2021 GameStop saga? I read on cnbc.com (mirror):

Tenev also advocated for real-time settlement instead of two-day settlement in order to help combat some of the chaos that occurred during the GameStop saga.

Why would using real-time settlements have helped combat some of the chaos that occurred during the January 2021 GameStop saga?
It would not prevent speculation driven bubble like GME but it would arguably prevent the situations such as Robin Hood being forced to restrict trading.  This is because when you buy stock your transaction is actually not processed immediately but takes few days to clear (usually 2 days see here).
This creates a problem because by law brokers like Robin Hood are required to keep portion of their own capital until transaction clears (e.g. SEC net capital obligations and clearinghouse deposits). This can cause a problem for a firm if people make too many transactions as it simply might not have enough capital to set aside to fulfil the regulatory requirement. In fact brokerage firms often raise additional capital even if they themselves not need it just because they anticipate that their customers could increase in trading activity but the volume of trading is not easily predictable.
This problem could be alleviated if stock trades were settled immediately instead of waiting days before actually carrying out the transaction. This is because if the stock trades are cleared immediately there is no need for brokerage firms to have capital buffers forcing them to restrict trading as the rationale for the regulatory buffer is to have some funds set aside if something happens in those 2 days.