Apple and Google both provide support for offline speech-to-text using local models. Users can configure it to be fully offline.
The Murena Voice to Text service in /e/OS sends the user's audio to OpenAI which is hidden away in their terms of service:
https://community.e.foundation/t/voice-to-text-feature-using-open-ai/70509

Voice to Text feature using Open AI
Thank you a lot for your positive and supporting comments about our new /e/OS Voice-to-text! Regarding its implementation in /e/OS, Iβd like to explain a few things to explain why we have chosen an OpenAI STT API to implement it and how itβs going to evolve in the future: What we have learned from our experimentations with STT models that run locally on the smartphone for speech recognition: they work quite poorly, they make a lot of mistakes in voice recognition they are not able to mix la...

