Why aren't Private Channels Setup as O365 Groups?

If Microsoft creates separate SharePoint sites for each Private Channel in a Team then why is there also not a separate O365 Group?  No one can access any files in these private Teams and Channels from Outlook because they don't show up a Groups and for some ridiculous reason, Microsoft decided to only show "Recent Folders" when browsing Web Locations, so it's impossible for users to email files using Outlook.

If Private Channels were groups, it would make memberships that much easier and then we can use Outlook to access the files.  All our users now have to use the OneDrive Client sync which is terribly bad with performance and files always get stuck not syncing.