For OneDrive for Business or Create MySite collection, we could disable creation of OneDrive for Business for Everyone via Microsoft 365 admin center>SharePoint admin center>More features>choose User Profile> Manage User Permissions>Select Everyone except external users then scroll to the Permissions section and untick Create Personal Site, then choose OK:
If you want to allow OneDrive for certain users or a group, you can add people or groups(If you are adding a group, this should be a Security group, not a Microsoft 365 group or Distribution Group) individually and then select Create Personal Site, click OK, wait for a period of time for it to take effect.
Note, above steps will not affect existing OneDrive sites that were created, If you need to prevent them from accessing existing OneDrive sites, remove Site Collection Admin permission of the user from OneDrive Sites.
For Delve, we could only disable the full Delve experience for all users in the tenant via SharePoint admin center>Settings>select classic settings page at the bottom of the page>then click Disable under Delve option:
If we choose to disable Delve for your organization, Delve will be removed from the app launcher for all users. When users visit a person's page, for example by clicking on a person in OneDrive, that person's page will contain only user profile information. No documents will be shown. Users can still search for other people, but not for documents or boards.
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