BP and a lot of kpop acts primarily get paid through tours. a 2 hour concert only needs 12-20 songs. why would they need to release more songs if they have more than 12-20 hits (dddd, aiiyl, forever young, stay, boombayah, pretty savage, hylt, pink venom, shutdown, playing with fire, lisa solo, jennie solo, rose solo, jisoo solo).
blackpink and bts are the only outlier where their bsides also get a good amount of listens. all their songs in spotify are 150m+. with the main songs getting 3-4x the listens. whereas kpop groups with great bsides like red velvet, twice, have their comeback single with 20x the listens of their bsides.
blackpink has been slowly getting out of the kpop bubble ever since they got their international fame. their songs are more westernized. their content release cycles are more westernized. (beyonce, rihanna, edsheeran, justin bieber, adele -- all the top artists hvae 2-3 years breaks between albums, sometimes 4++) their benefits and behaviors are more westernized.
fans keep asking for bsides and more songs. but the truth is. most kpop fans only listen to the comeback single. all the other songs are neglected. just look at the album listens =))