i still struggle with them though
For work not so much.
The only time a group chat worked was on a low budget film set where I worked as a camera operator, because people only wrote something there when they needed sth.
If your speech messages are concise and follow a bottom line first approach, this could be okay. After a certain length and complexity the other side will have to take notes. If you are not a clear speaker they will have to relisten and take notes.
Additionally speech is usearchable which could be very bad for the other side as well — imagine someone who has to listen through 10 speech messages to figure out what you said.
My girlfriend once had a manager who loved speech messages as well (I heard some of them). These messages were 15 minutes long, full of chitchat about her live and the workplace and somewhere around minute 9 the three sentences that should have been communicated to my girlfriend appeared.
My girlfriend told me that she wasn't the only person who would just completely ignore these messages with the sentence if it would be important, she would send us an email.
So if one is in a position where one can offload the burden of decyphering and searching for meaning in the words to others, speech messages are certainly comfortable for the sender. Sometimes they are also totally fine (e.g. to loved ones, friends, people where you know they hate reading).
But in most cases you are creating work for others — work multiplied by the number of receivers and number of times they have to listen through your stuff.
Imagine e.g. if you work in IT support and all you get is speech messages. That would be hell.
If you literally just typed out the same words you spoke, the recipient can 1) interpret your message faster and 2) search for it and find it in the future. Removing those two features for marginally faster message composing just seems selfish and a waste of the recipient's time.