Hi @Michael Winder ,
I don't recommend that you delete the General folder, as this folder is default site structure that gets created when you provision a team or office 365 group. This is by design. SharePoint sites are where the team's files are stored. And in Teams, the Files tab on each standard channel is connected to a folder in the parent site's default document library. Every team has a default standard channel, "General", which cannot be deleted or renamed, so the folder associated with it in the document library cannot be deleted as well.
You can view the detailed description of this article: Should I store my files in Microsoft Teams or in SharePoint?
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