> I get why people send voice messages: it saves their time, allowing them to record their voice while doing other things.

Is that the case? I know in signal on android, the voice typing features of keyboards are disabled as a security feature because these leak your message to google ASR apis etc. I use voice typing to save time and sore thumbs tapping on a touch screen. I can see how when that's disabled people might just record a message and send the audio instead. Maybe the solution here is to avoid the voice message all together and enable offline voice typing in the first place.