The only problem with audio/Loom messages is that it is not easily indexable, but that's a tooling problem that can be easily solved.
I rarely use email (I may ask someone to compose an email for me). In this setup, I do see value if I had a Slack bot that I could say to "ask lawyers for an update on X". But even then, people would immediately know that the email came not from "me"...
Personally, I'd like to see more tooling around
* using AI to auto-polish video/audio communication, e.g. remove long pauses, skip filler words, etc.
* summarizing video/audio/text communication into bullet points of intel and actions