Beyond a high school varsity player cannot kick as hard or as accurate is that the high school player would be much more apt to give away kick positioning through their body language, strike approach, and certainly their leg/torso positioning on a follow through.
As a goalie in soccer for 15 years and some for a top 25 high school I can say that there are kicks you can see before they leave the foot.
I compare this to a study that ESPN did a few years ago having major league baseball players try to hit softballs thrown underhanded. Because the players did not have any mental ques they couldn't get a bat on anything. Hitting a 95 MPH fastball was the years that they got used to release point, spin, arm action, leg follow through and so on. There is no way without this that their reflexes could react in time. Studies have shown in baseball that a player has to start their swing when the ball is 1/4th of the way to the plate.
I would imagine that a professional soccer goalie by that time in their life has seen possibly a million balls kicked at them. The best goalies will index things like strike angle, leg position, body position, torso turn, ball spin... And keep track of what the ball did based on all of these things.
A high schooler might be a dead give away just looking at their plant foot. If I saw someone plant early I would guess that they were pushing the ball and if late, pulling the ball. A high schooler would have a much much harder time hiding things like this, while maintaining ball speed, approach speed, and accuracy.