Most apps rationale for subscriptions is "Ongoing development" without an option like jetbrains etc. to fall back to a perpetual license. In practice, regardless of whether an app needs ongoing development or not, this is the best way to try to guarantee continuous income and make a living off of a project I guess.

Perhaps LLM's will force developers/companies to change their stance and to stop users from recreating what they have already created, just buy an at-a-time snapshot of their app for a one-time-fee? Probably not but one can hope.