At this time I don't think you can automatically add a user/group directly to a workspace from EntraId one at a time. EntraId can sync to the account, but then admins need to assign users/groups to workspaces. If you have identity federation configured, you can add users/groups directly to a workspace and they will be sync'd up to the account automatically, but I don't think you want that because you're still adding each user/group manually.
The ideal setup for you now would be to have one or more EntraId groups which you assign to a workspace once, and assign permissions once. Then just put users in the appropriate groups, and they would sync automatically. These groups would be designed for different personas, like "data analyst" or "data scientist" and have the minimum set of permissions assigned for them to do their job.