Chat bubbles in Teams meetings are another way to surface information. Using chat bubbles is a personal choice and it doesn’t replace the regular chat window. Microsoft says that chat bubbles make chat more central to a conversation, but it really depends on the type of meeting, the topic being discussed, and the number of participants. In any case, chat bubbles are there to be used if you want to.
https://office365itpros.com/2021/06/18/teams-meetings-chat-bubbles/
