The phrase implies a task takes a long time and lots of effort to complete.

Long Duration

It's used when someone is persistently working hard without giving up.

Persistence

The phrase connotes that the effort required is strenuous and possibly draining.

Used when two or more parties are involved in intense competition.

Reflects a situation where there's a fierce or vigorous struggle to win.

The phrase is often used when the result is not yet determined and effort is ongoing.