Not sure if I've ever posted to this forum before, but I just wanted to chime in on whether Astropad Studio is "worth it" or not. To me, it most definitely is. Warning: long post!
I bought Astropad before I even considered getting an iPad Pro. The app in itself was, to me, a possibility that an iPad (at the time, my old iPad 4gen, or an iPad Pro which back then was too big to even consider) might become my next drawing tablet. I was checking out Wacom's mobile offerings, but nothing felt really suitable to me.
When I finally caved in and bought the iPad Pro 9.7, Astropad was half the reason. Because; while I hadn't had experienced what it would really be like working daily with the app, I had kept a close watch on the development. Amazing improvements were happening, and fast. I started using the app more and more, and around christmas, I had gotten to the point when I was using my iPad more for commercial work and personal project than the ol' $1800~(?) Wacom 22''HD. By then, Astropad was simply indispensable.
So, when the subscription model was unveiled, I was in fact content with what I had. Like, it already had everything I could ask for. Still, there were no hesitations whether I should get a subscription or not. The original app had already made money for me – or, more accurately – it had allowed me to make money easily due to it constantly getting better.
I can now use the same gestures in Astropad and Procreate. I can storyboard, sketch, ink, whatever I want, and it's saving time as well as making work easy and fun. $64 is a bargain, I pay way more for Creative Cloud but would much sooner skip the latter subscription. If I suddenly go broke, it's not like the original app would stop working either.
So, no, I do not agree with your reasoning at all.