I feel like fillers or was it botox will limit her range and it was meh enough already. But it's not like Jun Jihyun Song Hye Kyo and Kim Tae Hee are known acting geniuses with various, totally different roles. There's a reason these 3 are known as the golden trio and it's all because of their beauty. They would rather retire than show up looking ugly in public. Wonyoung is the same with the way she is alert 24/7 and knows everyone is watching her move and acts cute/looks pretty all the time.
Pretty much 90% of korean drama actresses play almost the same role for years. You won't see them gain 30 kg/Viola Davis crying and are basically glorified walking advertisements. So Wonyoung can play a typical role of a pretty female lead who falls in love with the male lead and she's set.
I did read that their movie actors are on another level and are actually respected.