@nakamura
May I ask you:
-you are using subscription or in app purchases
What is average:
-subscription price
-in app purchase price
You are making $20 000/m, that would give me any idea how many users are needed to get such results

Better to find 400 people paying $50 than 4000 paying $5, but I may be wrong
usually I do:
weekly subscription: between 5-8 USD
monthly subscription: 13-18 USD (it is by far the least popular and in many apps I dont even offer monthly sub anymore)
yearly subscription: 44-59 USD
usually in the first paywall I offer a weekly subscription and a yearly subscription. No free trial. Fuck free trials, people should pay. I don't have good experience with free trials, most people IMMEDIATELY cancel the trial. They just want stuff for free. If you have API cost in any kind, do not use free trial, it will just cost you money.
then, after the people close the initial paywall, another paywall appears "blabla special offer you only see once" for lifetime. Price between 29-39 USD. Cheaper than the yearly sub)
depending on the app I also offer additional credits, token, coins, etc.
Overall, it really depends man. There is no solution for all. Each app or niche can have its own pricing strategy. You will have to test it. Increase / decrease prices to see how it converts, do the math.
Currently I have an app where free users HAVE TO watch rewarded ads. Many people just kept watching rewarded ads over and over again. Some of them watched 30 rewarded ads. No shit, they spent 30 minutes just watching ads. LOL. For me, it doesn't matter. Actually its good, the more time they spend on my app, the better it is for the ranking. I don't care if the money comes from Admob or through IAPs as long as it covers the costs.
You wrote "better to find 400 people paying $50 than 4000 paying $5"
I have people in my apps that made $5 weekly subscriptions and they have already paid $150+, some even more than $200. They totally forgot they subscribed to the app. On RevenueCat I can see when they subscribed, what app version they use and when was the last time they opened the app. They basically downloaded the app, subscribed, used it once and never used it again, but they still pay each week for 6+ months or even much longer.
If you want fast money, go for yearly / lifetime. If you want steady recurring income, go for weekly. Or do it like me: just do both. No matter if its weekly or lifetime/yearly, you still make good money