I’ve been using Astropad Studio for a while now and I really love it. IMHO, $80/year is less than what I spend on coffee, and it’s absolutely worth it considering the features and freedom it offers me. I have totally retired my Wacom in favour of Astropad Studio and my iPad Pro 12.9" w Apple Pencil.
I subscribe to Adobe CC, Basecamp, Xero. I also subscribe to cable TV, broadband, telco, water/electricity, etc etc. I don’t see a big problem with subscription services vs paid apps. At the end of the day we don’t own any of it either way. If something is a necessity, or adds value to my work/life, then it’s worth the investment.