For myself, generally: no. I'll support subunits/soloists if I like the music just as much as (or in some cases, more than) the original group's music, but a lot of those are exploring other genres and they don't always hit for me.
From (G)I-DLE, I
love K/DA and Yuqi's solos. Probably listen to them as much as (G)I-DLE's music. Miyeon's MY album is quite solid, but more mellow, so I have to be in the mood for it. And Soyeon makes fun music, but in general, I tend to prefer nasal-toned rappers in groups and find it a bit much on its own. Soojin's music suits her style, but none of it has quite landed for me.
For WOO!AH! and Purple Kiss, I'm pretty indifferent toward EL7Z UP compared to their original groups. Swan's solo was lovely, but I like PK for their creepy cute songs and Twenty is very different, so I wouldn't skip it in a playlist, but don't go out of my way for it either.
I don't think my other main faves have official solos or subunits otherwise.
And in groups that aren't my faves, there are a lot of subunits or solos I prefer to the main group, lol.
