On a group chat, the responsiveness is critical. You want the users to feel that other people are either reading them or typing a new message. You want to show activity.
12 tips for designing a better group chat experience
Max Masure
233

This in an important feature to messaging that I think people undervalue because it seems like such a little thing. I think this goes for both group as well as 1:1 messaging.

Personally I find myself waiting for a little after I text someone to see if the bubble pops up to show that they’re responding. (referring to iMessages)

One clap, two clap, three clap, forty?

By clapping more or less, you can signal to us which stories really stand out.