Don't sleep on Purple Kiss. Now that Mamamoo will disband after Wheein finishes her touring and promo duties for WAW... Purple Kiss is now the golden GG of Rainbow Bridge. I'm sure RBW will put a lot of promo and $$$ behind them. Mamamoo was arguably part of the Big 4 GG (without being in the Big 3 companies), so there is some sense to Purple Kiss being huge in the future. Swan is the next Hwasa with her thick hips.
I agree right now it's Itzy, G-Idle and Aespa. Personally I prefer Everglow but I have to be real and say they are not on that level.