Daesung is often overlooked but he was instrumental in getting BB's name out there with the older population during his Family Outing stint. Unfortunately the car accident in 2011 basically cut short his career as a variety star.
Taeyang solos havent done well post 2014 but he was always ranked high in those gallup idol polls. Always top 5 along with GD when they were active. ENL is also the biggest BB member solo hit. The public might not vibe with his music anymore but he's still well known and respected.
TOP was also v popular due to his acting and good looks, but he didn't put out any albums and obvs he took a huge hit with his drug scandal and now many people are afraid to associate with him. Hopefully being in Squid Game 2 can help him bounce back.
GD is GD.
Not as quite as drastic as Ive but I would say GD>>>Taeyang>TOP>>Daesung