@dorky_tae_123.
No, that is not true. You should not listen to snsd antis.
Yoona's voice cannot reach high notes, but she can sing very well~.
Yoona does not sing as well as taeyeon or jessica, but she has improved a lot!
Also, her antis are heartless, they make insensitive and mean comments about her singing. As a result, she herself feels insecure of her singing ability.
However, yoona has the cutest voice~ she sings very well~.
As for dance, it is out of question. She dances very well. She is the center of snsd because she dances very well~.
And about rap, I think all members are equally good at rapping!