Is <task-button> still required in task lists?

We prepend a <task-button> element to every task list item, but grepping the codebase at this point for task-button, taskbutton, looking for related files, I can't find any evidence it's actually used.

See:

• Add convert to work item button to description ... (#350062 - closed) which stated a need for it
• Add <task-button> for every markdown task list ... (!82547 - merged) which added it
• !212709 (comment 2907837407) where we wonder what purpose it actually serves