Hi Thomas,
I once did a thought experiment about only using team for private chat after a few people asked for this in the community. This included locking down every app
https://www.google.co.uk/amp/s/microsoft365pro.co.uk/2019/03/26/teams-can-you-do-private-chat-only/a...It’s quite difficult to do, but results may vary. There is a link in the article about OneDrive (you can’t hide it completely but you can restrict uploads) and with Planner you should be able to disable its use in Teams by blocking all applications with an app permissions policy (although you may still be able to access it).
The point I am trying to get to! Thanks for bearing with me
1.) Teams is a collaboration hub which is architected on Office 365 groups, when you create a Team it creates a SharePoint site, shared exchange mailbox and a one note in SharePoint for the wiki
https://docs.microsoft.com/en-us/microsoftteams/office-365-groupsBy turning off exchange online, SharePoint online and OneDrive (via SharePoint as OneDrive is a part of SharePoint) you are in effect removing functionality in Teams as Teams sits across those apps. Teams, in effect isn’t just the Teams app and the Teams experience is designed to work with other apps in the Microsoft 365 stack
2.) Because Teams is so integrated with a number of other apps via Office 365 groups it’s really difficult to isolate it from everything else and in doing so impacts the user experience. Best example is OneDrive, you can turn off SharePoint and PowerShell out the user permissions on personal sites which blocks uploading files but you still can’t remove it visibly from the file section of Teams. It gives a kind of weird experience for users. This is because it was designed to work with other apps but also the interconnectedness of the Microsoft 365 applications and how things like the portal is designed. It’s hard to do and often frustrating and users can often access things elsewhere which is inconsistent.
That is my experience, but hope it goes some way to answering your question
Best, Chris