Is it better to separate settings from task tab or to group it?

1. What's the difference between tasks and to do list in Outlook?
2. Is Microsoft Planner being discontinued?

What's the difference between tasks and to do list in Outlook?

A Task is.. a task. It's an Outlook item that is stored in a Tasks Folder. A To-Do is any Outlook item that is flagged for follow-up, usually flagged email, as well as all of the tasks in the Task folders in the profile.

Is Microsoft Planner being discontinued?

Planner is (still) Dependent on Microsoft 365 Groups

In 2022, this is less of an issue. We use Microsoft 365 Groups for almost everything, even if you aren't aware of it. If you have access to Team Channels or a SharePoint Team site, you're part of a Group.