Precise Question regarding Microsoft Project option connectivity

Hello guys,
hope everyone is doing well. I tried to find answers/questions but was unsuccessful. I hope that someone here could give me precise answers and thank you in advance.
MS Project to MS Plan Sync options:

1.  Direct updating from Microsoft Project Professional 2021 - Desktop Version to Microsoft Planner (365) (automatically creating tasks) that will become available to the team and then synced back to the Microsoft Project as they are working on it - Not available?

(Available is only to "link" the pre-created Microsoft Plan to the Task/ Part of the Microsoft Project without actual updating back to Microsoft Project Plan) - 3rd Party Options available

2. Microsoft Project Professional 2021 - Desktop Version+ Sharepoint Tasks is syncable and vice-versa updatable but SharePoint doesn't have a good collaborative Space for Team Members like Microsoft Planner?

3. When using the Project Online (Paid subscription) it is available to connect the Planner seamlessly, but of course project needs to be created in Project Online  from the screatch?

Thank you again