It's not relevant, because then the developer can release a new major version and require a new payment. The user will know exactly what changes this new major

It's not relevant, because then the developer can release a new major version and require a new payment. The user will know exactly what changes this new major version has, and can decide whether he wants to pay for it or not. With subscriptions however, this all becomes hidden/vague. You're always paying, but it's no longer transparent what exactly it is you're paying for. Which is obviously very bad for the user. (Of course it's a an entirely different story for services like Netflix, AppleTv+, Spotify, etc.)