My apologies, I thought it was fairly obvious. It is true enough that in a panic situation, you can grab/stomp the ABS and let the system modulate. That is not what I was discussing. I was discussing practicing hard braking.
With normal braking practice, you brake harder and harder, gently approaching the pavement and tire traction limits. With ABS, the practice is the same, but instead of the tires sliding, the ABS engages. So you practice under different conditions to become familiar with how the bike, suspension and tires behave, with less risk of crashing. Same practice, but there is a safety net with the ABS.
With proper situational awareness, the odds of needing the skills drop, but it is better to keep the skills sharp.