Are u new to these groups? Miyeon isn't the official visual, that's Shuhua and she's the most talked about member in Korea most of the time. Actually your point applies but with Shuhua lol
Seungkwan is the variety member and vocalist of the group, he's very known but he isn't part of the visual line in svt. And he's one of the most popular members even then
Eunji is the main vocal and most successful actress in apink but she was never the visual, that's Naeun but now that she left the title will go to Chorong or Bomi. And Eunji is always top 2 on popularity in the group
I am actually very new to kpop in general lol
How do you know who's the most popular member for example ? Using social media numbers ?