Nah, look at Oda. Dude could have retired years ago if it was just about money for mangaka.
Some mangaka are ADDICTED to drawing.
Big reason Oda is slowing down is because in his prime he refused to take breaks when he could have. Oda does love money, obvious (Nami simp), but he loves art more.
Obvious, Rental Girlfriend's Mangaka doesn't love his story that much. But, Chizaru?
Yeah. He wants Chizaru BAD. That's why he's always shitting on Kazuya in the manga: man wants to be Kazuya and is intentionally cucking and shitting on his main character all the time out of jealousy that Kazuya is the one "dating" Chizaru, weirdest dynamic I've ever seen an author have with their main characters.