Note: I know self producing is too big for kpop because it's not like the idols do the jobs all by their own 100%.
Anyway I think 4th gen bg still lacks of this despite the booming in self producing groups. We have gidle as the gg representative and they're doing really well. They're not from big 4 but Soyeon managed to make her music well known to public, not only fans.
But with bg, unfortunately when most of them trying to produce their own music, they still not capable to attract non fans to listen to them. And some of this groups is coming from the big 3. The closest one we got that well received but still not really a huge hit is Darari from Treasure, which is a very good song but I don't think they able to do that again when the said member that produce the song is now out.
Skz, the most popular self produced group in 4th gen also still unable to produce a hit song. They're known among kpop fans about their reputation ,but their songs is not really that well received even among kpop community.
We have Bigbang and Shinee from 2nd gen, Bts and Seventeen from 3rd gen. They have songs that gp knows and that is how exactly you know their songs will remember and future generation will know it too. But do you think any of this current self producing bg have this kind of songs and this is like what, already in the 5 or 6 years into the 4th gen.
It's really weird you know when almost all 4th boy groups labeled themselves as self produced groups, written their own lyrics, etc... yet it keeps general audiences away and uninterested with bg songs anymore. Maybe this is a sign to let the professional do their jobs because this clearly not really working?