At the moment I would rank the late 90s/00s/10s stars as:
Currently
late 90s/00s/10s girls
A+ Adele, Taylor, Rihanna, Katy Beyonce, Bieber, timberlake, Drake, eminem,
A Britney (flops pushed her down), Pink (basicness kept her from A+) bruno, ed sheeran, kendrick
A- (in limbo can go up or down based on their next era) Gaga, xtina, miley, Nicki, the weekdy
B+ JLO, Kelly Clarkson, ariana, nick jonas, Usher. Lil wayne
B Meghan, Selena, gwen stefani (solo), iggy
B- (in limbo can go up or down based on their next era) Demi, chris brown, ciara, fergie, nelly furtado
C Jessica simpson/Aaron carter/hillary duff