Provide the user the option to login in to any product that they have access to if they are using a SSO. Once they login to a project, provide them the ability to set their default page to render.

Dashboards are only in the context of the product. However, if you have Confluence, you can create your own dashboard, that provides a portal into all the other apps or any other enterprise app that users may have.

This would provide significant value to users to minimize some of the frustration of where to go for what as admins would be willing to invest the time in creating a default starting page (if a user didn't define one) to help them determine where to go for what.

If they didn't have SSO, same is true in that they could set a default starting page at least within their product (e.g. they may always want to start in a specific project, space, or board).