Sakura is a huge reason le sserafim are selling as much as they are. She still has the biggest fandom which is going to take time for the rest to build up. She still is the most popular in the group. You just don't lose your popularity like that. Kazuha does have a lot of attention which is great. One place she is out doing is SK. But yes kazuha may end up catching on faster with next few comebacks.
Also some of you need to stop this wonyoung vs sakura stuff. It's you who thinks she needs to beat wonyoung.