Tasks are on a per User base, even if a sequence initiated by another has set for the tasks to be assigned to a specific user other than themselves. At present, tasks are only visible in the Sales Inbox for the individual user they are assigned to. In case you are seeing a lot of tasks assigned to you, then inside one or more of your sequences you likely have your task templates hardcoded to assign the tasks to you.
For example: If you are using a 'Distribute Leads' step as an initial step in a sequence, and you want the subsequent task steps assigned to the respective Contact Owners that are selected in the 1st step, you would want to change those subsequent task steps templates 'Assign To' field to - 'Contact Owner' instead of the selected specific user profile.
As the initial 'Distribute Lead' step will randomly assign the selected users, 'Contact Owners' selected under the step to the enrolled contacts. On changing the 'Assign To' field under the task templates to 'Contact Owner' those tasks will show under those specific user-profiles and not clutter your inbox.
How do I track my user's task completion?
If the tasks are generated via Sequence, the Sequence 'Stats' will allow you to see the progress on tasks created versus completed as shown in the screenshot below.
Furthermore, the Reporting Module would allow you to create 'Task Reports' specific to each user to see tasks assigned, completed, etc. You will be able to set up a report to view tasks in whatever form you'd like. For example, if you want to see the total tasks completed for a specific user, you would be able to set this up under Reports (on the left panel). Here is a quick video on what it looks like to build that report.
Lastly, we do have a dashboard that will give some more insights regarding tasks per users and such for the Admins.