The real money maker is in goods.
A genuinely high quality anime takes time and money to make. Otaku fan service can be churned out along with loads of cheap knick knacks. There’s also the whole gacha game industry which ties into those series.
K-pop is similar. People obsess over a band and not only buy an album, they buy an overpriced can of coffee with a picture of their favorite star, a shirt, a bracelet, order a bag of cookies they shilled on their Instagram, and so on.
A school aged boy has to beg his parents to buy him a tshirt with an anime he likes. An adult Fate or Love Live fan has no problem throwing down $500 for a new figure or $80 for a “limited edition” Bangladesh-made bag. They’ll happily do it monthly.