The presenter pointed out that the LNER Azumas, though limited in top speeds to 125 mph, have an 80 mph average speed. Looking at the latest RPA timetable, it appears that the Acela has a 61 mph average speed Boston - New York (thanks, Metro North!) and a 76 mph average speed between New York an Washington, despite having a higher maximum speed of ~150 mph. The Northeast Regionals, with a 125 mph top speed, have a 54 mph average speed between Boston and New York and a 62 mph average speed between Washington and New York. "Washington" and "Boston" here refers to the cities located in the northeastern United States of America.
It seems to me that it would be a better use of limited funds to work to increase the average speed rather than try to increase to top speed.