Only problem with that statement is it not true. Stock Market has not lost "much of its revenue". It still retains 80% of the value it has added since it low point in Oct 2002.
And - I can wouch for that - is that the revenue part continues just fine. Brokers, clearing houses, financial advisors, hedge funds, their revenue continues just fine.
The stock market per se doesn’t have revenue, it has money flows, and they can be positive or negative, but the participants/enabling companies have plenty revenue as long as there’s volume.