Drastic has been around for a long time, and for a good while, it was the best supported one on Android. It was definitely worth the flat, one time $5 charge that I paid like 10 years ago.
Really, that's the ideal: flat, reasonable charge for lifetime use of the software that is still getting updates a decade later.
But realistically speaking, the dev hasn't actually done much work on it in the last few years beyond bug fixing (not that there's much left to add in the first place). The price wasn't terrible but the insistence on the keeping it paid hurt the ability to sideload it when you needed to. It should have been free a long time ago, especially after it got so much competition.
This timing is very interesting with the Yuzu/Citra shutdown - do you suspect the change has anything to do with not want to make money from a Nintendo emulator as be less of a target? Or is there something fundamentally different about Drastic?
I will add that I don’t mind if, on top o the flat rate, there is a few years of free updates until you have to renew your license, as long as you can keep using your “outdated version“ for as long as you want. I see this model in many professional apps I've used over the years (Sketch or Affinity apps for example) and I find it very reasonable because I understand that ongoing development requires investment.
Maybe you went to somewhere like APKmirror or some other site to get the APK because you refuse to pay them find out you really like it and want to support development. I've done something similar before with steam games, which isn't the same thing, but they're both in a similar ballpark.
Well, Drastic is on the Play Store. Citra wasn't last time I looked (which wasn't long ago because I wanted to play Phoenix Wright again) So anyone who doesn't know how to or doesn't want to sideload .apks would be my guess.