The no sit transfer rule has changed things. But JuCo transfers have always existed.
Halfway through freshman year my son won a starting position. It took two upperclassman failing first. He hit .300+ with speed and gap power (hit 3 homers in 120 AB’s). He returned soph year to find a JuCo All American at his position. He had to win another position, and did.
After essentially being the same player with full season stats soph year there was a Gatorade POY at his position the next fall. He won another position. Junior year he established this is where I bat and this is where I play.
The song “I never promised you a rose garden” was written for college recruiting.