The short answer
Because macOS changes, speech models improve, and writers deserve software that keeps showing up. Your subscription funds compatibility updates, better dictation and formatting, privacy work, and actual support — not a dusty download we promise to remember. Cancel anytime; your words remain yours.
And the free tier is real
The subscription pays for the parts with an ongoing cost: cloud transcription and cleanup, and the work of keeping the whole thing current. The on-device engine stays free and fully functional — a free account gets you 10,000 local words every month, no payment info required — so the honest answer to "do I have to pay?" is no. Pro is there when the cloud engine, and unmetered local dictation, earn their keep for you.