Retton was the first woman to win the all around gold medal. She was and still is hugely popular. She was also a big supporter of Ronald Reagan. She set the table for Biles by inspiring a generation of girls to take up gymnastics. 10 years from now Biles will be a name in a record book and not much else.
Yes, Retton was the first U.S. woman to win the all around gold medal (against a field that didn’t include the USSR). Yes, she was and is very popular. She also supported Reagan, not that I care about the political views of athletes.
She had 1 gold, 2 silver (team + vault), and two bronze (bars + vault). She also never competed in the World Championships.
In the Olympics, Biles had 4 golds (all-around, team, vault, floor) plus a bronze (beam). In five World Championships, she won 19 gold (include 5 all-around), 3 silver, and 3 bronze.
Their records aren’t particularly close. Retton pulled off one amazing victory. Biles dominated the sport from 2013 - 2019.