Not offline, but more secure (maybe?) than a random WebApp, is the Transcription option in the online version of Microsoft Word. If you have Microsoft 365 via

Not offline, but more secure (maybe?) than a random WebApp, is the Transcription option in the online version of Microsoft Word. If you have Microsoft 365 via your employer, you can transcribe up to 300 minutes a month. I use it a lot for recorded work calls, as my memory is awful. I just wish they'd roll it out to the Desktop version of Word, as the online version struggles with transcripts longer than 50 pages.