Activity summary on start up
On startup it would be nice to get some kind of "since you last was here"...
I.e summary of all your teams, activities and chats. Like Planner Hub combined with a bit personalised insights and perhaps a short summary of current tasks, answers in chats, calendar summary.
Part of it exists in "Outlook today", Planner Hub and My tasks (Planner). But build on that with Team centric information and display it all on a "start up page" or "My page/profile".
Sheerie Gray commented
Have it like a bit of a dashboard whereby you can have different "widgets" and you can customise the dashboard and the individual widgets?
Brad G commented
You could also add the Summary option as a filter in the Activity section.
Also, when selecting a team - have a summary page shown that summarise the activities within the team. That would greatly increase efficiency since you with a quick glance can get the overall view of what's going on.