In K-pop, many artists come and go. There can be as many as 50 new groups debuting in one year. Many groups disband after only one release! These days if a group does not continuously promote, they will be soon forgotten about. This is a sad reality in K-pop.
However, there are some groups, who despite not promoting in Korea during long hiatuses, are still holding on together as a group. They may even randomly perform at events every so often. Some do better in Japan and decide to stay there. However, fans can't help but feel the ache to see them in Korea again.