Hi @john john
Microsoft will continue to support CSOM and REST API. You need to choose different API for different development scenarios.For Front-end development(like SharePoint FrameWork...) you could use REST API or Graph API,for Back-end development(SharePoint Addin),you could use CSOM and REST API. Currently there is some function Graph doesn't support. You can raise a ticket in User Voice. With requirements like this increase, the problem may well be released in the future.
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