I am a whisker taller than 5'5"
In 1997, I had a couple of health scares, and career malaise going on.
I hired an amazing personal trainer in March of that year. I was fat, and pretty lost.
I started a pretty basic conditioning program that consisted of a lot of cardio, and some base building
weight training. In the ensuing months, we started real athletic training, with plyometrics/speed/etc training.
By August, with the exact same equipment, I had picked up a full club in iron distance, and 8+ yards carry with my driver.
After a 2+ year injury sabbatical 1998-99, I came back to play a bit in 2000. In one day, I took my old 1997 era driver/ball to callaway, to get fit for the new generation, and picked up 10+yards carry by optimizing my launch and spin much higher.
Personally, my belief is it is about the whole package. Kids are training smarter and harder in every sport, golf included. The equipment is more forgiving and we learn something every day about fitting/optimizing better.
I hit my old MacGregors pretty damned close to my Callaway...when hit solidly. It's an inch shorter, and launches way too low, but I am surprised how far it goes TBH.
The genie is out of the bottle, and the genie's tentacles cover equipment, fitness, agronomy, and aggressiveness created by all of it.