[r00fus]

What makes email inherently better for your React/Respond dichotomy?

What prevents redundancy is searchability. Most email clients are great for that, but Slack's searchability is inherently better than email - if you're not part of a channel (because you weren't on the team at that point), posts can be searched once you do gain access to the channel.

Emails between other team-members excluding you cannot since you will never have access to them.

There are so many times I just link back to a previous answer on the topic and just h/t the original poster. Takes a moment, but is far more definitive.