FAKKU has several different products that are not all related. You should think of the subscription as one of them, and not an overarching package.
I've already written a post about this, detailing what those different products are.
FAKKU's Products
Basically the subscription, even from inception back in 2015, was never meant to cover everything. In fact FAKKU started publishing books long before the subscription came into play. It's somewhat similar to Amazon Prime. Having a prime membership includes a bunch of digital content (video, books, music). But if you want to get a Blu-ray, for example, that is an entirely different product and is sold separately.
It's also important to note that the subscription has never slowed down. There are simply more products available for sale now than there were a few months ago. The subscription is no worse than it used to be.