Enable integration of Microsoft Teams to an existing SharePoint site rather than to always create a new site collection
There have been a few ideas raised on integrating lists, OneNote, document libraries, etc. from an existing SharePoint site with Microsoft Teams, but in summary, it will be best if we could create a team upon on existing site, so that the "Files" and "Notes" tabs would directly reference the existing document library and OneNote in SharePoint. It does not make sense to have two separate sites: one for all the usual SharePoint stuff, and another just for Microsoft Teams.