That sounds like a problem, but as a customer, I see that as a feature. I do not want to be mailbombed by everyone who has ever written an app I used for some time in the past.
And there are other features that I’d like as a customer that Apple will not let developers offer. More payment options, for example. Why not have the choice of multiple app stores and let the market sort them out? We’ll see the best ideas adopted by all.
The other side of the coin is the app can’t refund from their side, nor stop your subscription or fire you as a client either. They need to wait for you to do it, which can brew complicated situations.