I think you’re going to have a hard time competing with the major cloud providers on transcription alone. AWS Transcribe, for example, is quite easy to use and supports batch transcription as well as streaming, custom language models, etc.

There’s still quite a bit of value-add possible on top of that, however. The ability to edit transcriptions is a great start, especially if you maintain timecodes against the media. Developing or curating domain-specific language models to improve accuracy is also a likely option. There also appears to be a lot of interest in using real time transcription to augment live events with content derived from the conversation.

Good luck!