Do Jpop idols make more money than Kpop idols?

yes. Japan Market still one the highest on hard album buying.

And the longevity of the artist is higher than kpop idols. You can have long career as an idols as long as 20 years.

Sakura and Hitomi switching to Kpop, even though they were top members in their old groups, really says a lot. Even Nako has pretty much moved to acting after graduation, and they’re all still young and in their prime after Izone. In reality, idols industry in Japan is in decline now. Back then, Japanese idols used to make more money than Kpop idols, but that’s not really the case now.

I think Kpop groups make more money these days because, besides earning in Japan through tours, commercials, and merch (like Japanese idols), they also rake in cash from other countries. Kpop companies are smart at coming up with ways to squeeze extra money from fans. The Japanese entertainment industry—except for anime—is hard to access, and they’re not as open to international fans, so their idols don’t have the same support. If they flop in Japan, that’s it. But even Kpop boy groups that don’t chart in Korea or aren’t well-known can still sell hundreds of thousands or even millions of albums, all thanks to international fans.

siyeon of qwer left nmb48 because there was no pay even after doing gigs and photoshoots

she was not popular though

Just guessing but I think the more successful kpop Idols earns more, but if you come down to the tier under the top maybe the japanese groups earn a bit more because a bigger domestic market where even the middle groups can sell enough to get some money.