Who are the most improved idols!!

Tzuyu was never bad to begin with. She always had the potential, she just didn't train long before she debuted (Mina too). She goes out of her way to improve by still taking vocal lessons, even this far into her career, and her hard work has paid off. Imo her, mina and chaeyoung are the tier directly below 3mix vocally. Sana has a very nice vocal tone, and she benefits from having a naturally high voice but her and Momo both struggle with poor technique and bad vocal habits they've developed over the years (from being forced to sing in ranges they aren't comfortable in).

Great to see all this improvement.

I think Jin greatly improved his singing

doyoung from NCT was good at singing from the get go and he has only gotten better.

Sakura's dancing and stage presence easily the biggest improvement of any 4th gen idol. Wonyoung vocals as well.