It makes a level playing field, but Serena still had an advantage-she had the emotional support form the crowd, Andreescu had to be mentally tough to fight that hostile environment.
Level?
Serena is nearly 40 years old, and has been playing for a year since giving birth to boot. You call that level?
Notice what has been happening to Federer? Quite a few are surprised Serena is still even making finals. However, that is when she crumbles... since coming back to tennis. And the advantage you speak of is a hindrance to Serena. She has the extreme pressure of getting number 24 with age catching up on her. In fact, it already has!
Did most of you guys start watching tennis yesterday?
Tennis has been a young person's game since way back when. Most of a tennis player's best work is done from age 16 to 25. I'm sure you'll find more slam winners in their teens than post 35!!!
As but one example, Martina Hingis won all of her 5 slams by the time she was Bianca's age.
Steffi Graf? When she was 19 she had 5 titles as well, I believe.