I get the auto-transcript with yt-dlp then ask a cheap LLM like DeepSeek to clean it up.

Though lately I've been uploading the audio to AssemblyAI, I somehow still haven't used up my credits after several years lol

At one point I built a system that would summarize the transcript and I'd be able to ask questions about it, but Gemini can do that natively now so I usually just use that.