The Catholic approach is economical: it's expensive to keep dying people alive if you need resources to do so, but a religion promising eternal paradise is going to have a real propagation problem if a significant number of adherents commit suicide - and trying to carve out euthanasia exceptions wasn't going to play well to medieval peasants.
This is an odd take considering the Catholic church via the Vatican was one of the most powerful and wealthiest organizations in Europe for many centuries, able to topple monarchs.
The point stands: if your argument were true of the Catholic Church being ruled by money and doing whatever it economically can do to propagate, the Church would behave much differently than it currently does. But, the Church is not doing everything economically possible to propagate today, so there must be some other ruling principle.
"economics" doesn't mean "money", it means the allocation of resources.
You're treating this whole idea as though there's a nefarious organization deliberately managing things (which there is in some cases, but the why is unacknowledged).
But a cell in your body has an energy economy that means it adopts certain strategies based on it's constraints.
Similarly, successful religions have an economy of beliefs that they have to adopt based on constraints. Almost all religions portray an afterlife, so all religions have a problem where they need to stop people short-cutting to get there - otherwise they promptly stop existing. But then they also have followers with limited resources so they also can't preach infinite life-extension since that undermines the afterlife narrative, and is economically unfeasible for followers (particularly since you also need to collect donations to your church to keep the organizational structure running).
A belief is economical if it exists today, and existing beliefs are economical. This tautological line of reasoning doesn't help explain the Catholic approach to anything.
What's tautological? How are the Branch Davidians doing? Heaven's Gate?
I note you keep insisting "they would change beliefs" but you've neglected to ever include what changes you think would obviously disprove this hypothesis.
