it's a well known fact that boy group are more sustainable than girl group and its been like that since 1st generation, although most girl group reach higher peak during their career, but it didnt last long thus lead to disbandment. for example, the only active 3rd gen girl group are TWICE, RV and OMG. MAMAMOO will probably do comeback 1.5 years per comeback and god knows whats the fate for BLACKPINK.
when i said sustainable, it didnt include "special" comeback like KARA and SNSD, but more like consistent & frequent comeback like Beast, SHINee and TVXQ. do you think theres any ways for girl group to become sustainable a.k.a frequent comeback? why cant girl groups consistently promoting as a group just like other 2nd gen boy group, even if they are not doing as well as before?