I think this is a problem inherrent with a lot of ‘reply’ based conversation. The only solution I can see would be to remove the nesting. A forum like conversation. Where instead of responding to individual people you respond “next”. Wherein you could make a large response after seeing the many replies that would enable you to address them together. It would allow people to see that you’ve addressed them together and reply with new responses rather than replying to your original thought.
Of course such forum based response systems have the other problem of making it difficult to track a conversation if it gets long. It becomes hard to see who has responded to the original thought vs who is responding to new thoughts.