The American, generally acclaimed as the greatest gymnast of all time, lit up the Bercy Arena with her limitless ability and winning personality.
She led the US team to gold, won the all-around title and the vault, but on Monday fell and failed to win a medal on the balance beam.
She had to settle for silver after mistakes in the final floor exercise.
By her stratospheric standards it was an average day in the office.
"There were two big mistakes on the second and final jumps (on floor) and she lost .600 points which cost her the Olympic title," reflected Landi.
"She wanted to give it her all as she was a little tired -- as a result the control she normally has on her landings wasn't the same.
"I think there's a little disappointment, but with a silver and three golds we can return home proud."
Landi's husband and fellow coach Laurent said: "The most important was the team and the all-around, anything after that was a bonus and I was beginning to see she was tired physically and above all mentally, it was beginning to get tough."
Biles appears to have left the door open to competing at her fourth Olympics in Los Angeles 2028, saying this week "never say never", but not if she listens to Laurent Landi.
He suggested: "My advice? Have a child, have fun and live a little.
"Why do Los Angeles? To do better? That's enough, at 27 it's not bad, it's up to her but in my own opinion with 41 world and Olympic medals she can call it a day."
Biles's achievements stretch far beyond the sporting arena.
The way she handled and spoke so openly and lucidly about the mental issues at the Tokyo Games that forced her to pull out of most of her events is a legacy that will endure long after she retires.
"I think that putting your mental health first and taking time for yourself whether you're in sports or not, it creates longevity in sports specifically but also for just a better, healthier lifestyle," she told Monday's post-finals press conference.
"So I think it's really important that we put our mental health first and then everything else will fall into place."
