Here's the full article: https://www.ft.com/content/e8dc2264-6b8d-4ed5-8bbd-e4a67e7d1e46
"The pipeline of new candidates has thinned because university accounting courses have become less popular in the US. Graduates’ starting salaries can also be at least one-fifth higher in finance or technology, and those careers may not require such an expensive professional qualification. “With the length of time it takes to become a partner, the length of time it takes to achieve financial success, the financial model of CPA firms is archaic,” said Alan Whitman, who ran the accounting firm Baker Tilly for seven years until March."
Add in the extra year of college needed, long hours and gruntwork for newbies at large firms, perception of boring, etc.