Depends on how you use it.

A few years ago I used to have an IDE template that was like

  // TODO ($username $date) 

It was great and a central part of my work flow. I'd just leave them in the code whenever I saw something that needed fixing or could be improved, and every once in a while I'd just grep for this string and get my todos.

Some stuff was urgent, some was to be fixed later. Some never got fixed, but because it was all timestamped, it was easy to identify and clear those out. Also saved my coworkers the git annotate archeology to figure out who wrote the TODO and if they wanted additional context.

This flow felt extremely productive. Being able to just drop these when you think of something reduces the context switching. It also becomes an implicit bookmark as to the code the remark applies to (unlike jiras that are typically not well integrated into the code). Creating a jira is either an expensive context switch, or something you postpone and typically forget when you're done with the task and even if you don't, you've wasted a lot of cognitive energy keeping this in the back of your head all day.