Surprised to see how many other small projects doing this same thing there are. Kinda seems like a solved problem with ListenNotes. Not affiliated, but I use the service a lot and they have a lot more features than just transcripts including publicly accessible APIs (some of which could probably be utilized by some of the projects posted here)
In addition, it's free for users and the API's free plan is sufficient for most personal uses. Hard to see how any of these newcomers could compete unless they had funding behind them