This is correct and
as per my last post, scheduled travel time has not decreased in previous years. However, what has decreased is the gap between the desired arrival time and the next-earlier arrival offered at the destination and between the desired departure time (for the return trip) and the next-following departure offered.
When seeing travel time as the time elapsed between actual departure and desired arrival on the way to your destination and between desired departure and actual arrival for the return trip, then filling these gaps with additional frequencies might have saved some passengers 2 hours per direction, thus more travel time saved as by building HSR and virtually zero infrastructure investment. Prioritising higher
frequencies over higher
speeds is therefore a much more cost-effective way to increase the utility of a passenger service offered and, very conveniently, builds the ridership you'll need to eventually justify HSR.