You can’t just look at a course without factoring the speed.

The PR as a full day casual cruise. Maybe stop a time or for a beer would not be hard. To absolutely hammer the same thing at 5% below your absolute threshold for hours is probably hard.

Look at a downtown crit. It’s not hard to ride around the block. That sure doesn’t make crits easy.

There are only a handful of rides that are extreme regardless of pace. Like those death defying red bull vids from southwest Utah.