Crossfit is a cult.
I find that humorous.
Some that I occasionally workout with are of the opinion that Crossfit training is too much too soon and does not have a sufficient warm up. Max effort in min time.
For a long time, if I do not have a hard sweat, my knees are not ready for HIIT.
Minimum twenty minutes then ramp up.
Their greatest act of stupidity is high rep Olympic lifts after running a 400 or 800m.
Form is key in the Olympic lifts.