Recorded speech to text conversion for Mac

In the past I have been using Dragon Dictate Naturally as a a “speech to text” conversion software.
Unfortunately it only works in a Windows environment.
There seems to be no Mac counterpart available anywhere.
There is of course the dictation software built into MacOS and iOS but for longer texts the software is laggy and slow.
A major disadvantage of the Mac dictation software is that it only works with direct speech. There seems to be no way to make it work with prerecorded speech (as a mp3, wmv or other file) apart from performing an audio playback from the recorder into the microphone which is completely ridiculous.
Any suggestion would be very much appreciated.