Did more girlgroups find success in 2nd generation compared to 3rd generation and why?

Second generation in general appealed more to the public, girl groups and boy groups were dominating the charts even smaller groups could easily be on the melon 100 charts, but now days only a select of idol groups can do that .

Success is relative. When's a group successful, when isn't it successful?

Also, there's a distinction between success or popularity in South Korea, and success worldwide.

The larger popularity and recognition of K-pop worldwide has caused a lot of K-pop groups to do well, many more of them do as well as or better than K-pop groups used to do globally in 2nd gen era.

You can also see it in album sales, even rookie groups and less popular groups are able to have album sales that equal or surpasss the album sales of most groups in 2nd gen era.

In South Korea however, idol groups and idol songs aren't as popular as they used to be at the peak of 2nd gen era.

At the peak of 2nd gen era, the Korean annual chart Top 20 was filled to bursting with K-pop songs and K-pop groups, and not just the same handful, but all kinda different K-pop groups, girl groups and boy groups.

I think that was K-pop groups' most popular era in SK and with South Korean general public: K-pop groups and idols were everywhere, a huge presence in all kinda popular variety shows, they were a hype.

The past years that hasn't been the case: only a few K-pop groups reach the Gaon annual Top 20, and only a handful K-pop groups are a recognisable presence to the South Korean general public, outside of K-pop fans.