To each their own, but I find this decision really misguided.
It's her money, not mine, so whatever, but l do not expect her to turn a profit in, rather the opposite.
In my view, the cross section of "IfR" users and people willing to subscribe monthly is rather small (especially if the money mostly goes to reddit - assuming I could afford it, I, for instance, would rather fund an open system like Lemmy).
And if Apollo's dev Christian Selig decided that it wasn't worth it with an already established paying user base, who already has a strong culture of subscriptions and exaggerated pricings, and one of the highest volume of users, at what probably was the peak usage of the platform; I don't see how a small app like IfR can survive.
That, or he made a pretty expensive mistake...
The devs were hoping that they can keep their apps up and their livelihoods without too much additional work, that's fair from them I suppose. But they should definitely be taking a hard look at porting their existing apps for the Fediverse, if they aren't yet.