Help understanding some animation code

Unity Engine
1

Been following UnityGems for a while - in Coroutines++ - they wrote an example of a WaitForAnimation method - here;

//Wait for an animation to be a certain amount complete
IEnumerator WaitForAnimation(string name, float ratio, bool play)
{
    //Get the animation state for the named animation
    var anim = animation[name];
    //Play the animation
    if(play) animation.Play(name);
 
    //Loop until the normalized time reports a value
    //greater than our ratio.  This method of waiting for
    //an animation accounts for the speed fluctuating as the
    //animation is played.
    while(anim.normalizedTime + float.Epsilon + Time.deltaTime < ratio)
        yield return new WaitForEndOfFrame();
 
}

Here’s what’s keeping it a mystery to me: why did we add float.Epsilon and Time.deltaTime to the while condition? - wouldn’t it suffice if we just said while (anim.NormalizedTime < ratio) - it would make more sense.

in their downloadable project files scripts - they wrote the condition like this:

 while(anim.normalizedTime + float.Epsilon < ratio)

I know that float.Epsilon is the smallest float - used to compare if 2 floats are reasonably the same - but why is it used here?
why did they get rid of Time.deltaTime? - thanks guys.

2

Anybody home?