Often, we are multiple people collaboration on one tasks. However, it is only possible to assign the ticket to one user. Therefore, when filtering your tasks to only seeing “Just my tasks”, the tasks you collaborate on are not shown.
Therefore, I suggest to be able to add multiple assignees. I understand that it can be a risk to add multiple people to be working on the same task, but a solution to that is to mark a lead or a primary responsible for the task.