Its hard to argue but you're right. Companies will only produce what they believe will make them money. Unfortunately, the only group that pays for manga and anime usually is the preteen boy that hasn't really discovered p@rn yet. Older audiences usually find free ways to obtain it or dont have the free time to really get financially involved. So publishers just publish ecchi harems, OP isekai, and high school romance.
Deep and well written manga and anime that target more mature audiences just dont make as much money, it would need a cult like following or a company willing to take a financial hit for it to be able to finish its run
You seem to be someone who has matured beyond the paper thin, cookie cutter harem that is vomited out every year and is looking for more. There are some out there, it just takes more digging to find. I am personally not super mad at companies trying to make money (I support the hustle) I just wish there were more chances for people to get their works out there without it having to be haremized and sexualized