How does this method work?
Subscription becomes meaningful when the viewer expects value from the same channel in the future. Once a video works, if it is not clear what else the channel has to offer, the person may not subscribe. That's why the promise of repeatable serialization and open publication is important. Instead of calling subscribers every few seconds, give the viewer a concrete reason to continue.
Evaluation with a concrete example
For example, saying 'we will test the winter conditions of the same route in the next episode' at the end of the route video tells the right viewer the reason for continuing. But you must be able to actually deliver on this promise. Examine your subscriber gain not only by the total number but by which videos contributed. If a topic that brings a lot of subscribers is unrelated to subsequent broadcasts, the channel promise may dissipate.
Your first application: what should you have?
Check the visible part of the channel for a first-time visitor: do the description, featured video and playlists cover the same topic? Create a three-part series and give each episode a natural transition to the next related content. Subscriber exchange and using dummy accounts. Your output is a clear broadcast promise that explains why the viewer will come back.