You May Not Always Have a Phone Number for the Contacts in Your Call Tasks, so This Filter Allows You to Consolidate Your Task View
Because call-based tasks can be created automatically from sequences, having a lot of contacts without phone numbers can easily cause your Tasks view to become cluttered. You cannot complete a call-based task if the given contact doesn't have a phone number, so the 'Phone Number' filter allows you to remove these from your view.
To do this, open the 'Contact Filters' section of your Tasks page and then use the filter shown below -
Once filtered, you can then proceed through your list of tasks without having to worry about coming across any that you cannot take action on -
Taking this one step further, you can also leverage the filter as a way to manage and remove the tasks you cannot complete. Specifically, if you instead filter for 'Phone Number' > 'Contact has a phone number' > 'No', you'll be able to list them all out so that they can be skipped -