Why the agents are paid
An agent editing your video queries a language model hundreds of times: to read the transcript, pick a take, place a cut, check a level. Each call has a cost, and it climbs with the length of the footage. That is why there are two plans, with a quota in each.
The subscription pays for that computing. What is left funds the development of the free app, the one everyone downloads without paying anything.
The code stays open. You can download it, read it, change it. The free version ships without agents: if the agents do the editing, the subscription applies.