mp4grep works and I've been using it but it has some unnecessary features if this is all you want to do (it's mainly designed to cache the transcriptions and let you search them rather than just write them to a text file) and hopefully someone will make a simpler command line transcription tool.
I wasn't able to play with https://github.com/o-oconnell/mp4grep on ARM.
https://www.maketecheasier.com/enable-live-captions-ios-maco...
Google meet also has it built in on the client.
Edit: previously incorrectly linked to https://support.apple.com/en-au/guide/mac-help/mchlc1cb8d54/...
Details: https://www.maketecheasier.com/enable-live-captions-ios-maco...
OP mentioned multitasking so maybe they had a similar version of this problem. People aren't going to be happily recorded just for the purpose of someone wanting to preserve their own energy during meetings.
Okay, so maybe it's best if you don't do it then?
It's a bit like those 'wait I can explain' situations in sitcoms.