Locate individual chats in the bottom bar, in order to be able to talk with someone without leaving the page you are working on. Now there is nothing on the bottom bar, and is very annoying to close your current page to answer some message of your colleagues. Usually this conversations are short and the effort of going to "chat" tab is bigger than the answer to write. Having some chats opened in the bottom bar, always visible, will improve the working experience. I thin MS Teams has this feature.