The Google Pixel 4 has a unique Recorder app that can transcribe audio to text without the need of an internet connection. So far the app has remained exclusive to Pixel 4 owners but according to a Reddit post from an Official Google Account, the Recorder app and its auto transcription functions will come to older Pixels via a future software update.
The post did not give specifics such as which devices will get the update nor when itís planned to come out. This is still not officially confirmed elsewhere by Google but it would make sense for them to bring the Recorder app to at least the Pixel 3 line. Either way, we'll keep you posted once more info emerges.