This is a separate idea to Reminders for tasks. This is not about being reminded to do a task.

This is an idea that, when you next open a task, you get reminded of what you were doing last time you were active on that task.

E.g., you are working on a task and get to a certain place. You need to stop, but want to be reminded of what you were doing the next time you open it.

You could create a message to yourself that pops-up when you open it.

Yes, you could use the Task Description or Comments. But the trouble with these is you have to actively look for them.

A reminder would pop-up and remind you without you having to remember to check it.

It's similar to the feature you have on some phones where you get location-based reminders that pop up when you are somewhere.

Instead, this is task-opening based reminders with a custom message to yourself.