Any drawbacks to swapping the SpriteRenderer.sprite each frame instead of using Unity's animator or legacy animation?

Hiya. I've written my own code for animating background elements in my game. Not actually sure why I bothered now, it seemed easier at the time to do it this way, so that I could control the animation using coroutines. My script is probably going to have less of a performance hit than Unity's own animator, but what about compared to the legacy animation (if that's what making animations using the Animation window is?). Or another method? I searched around and found SpriteManager, but it's just a little bit too complex for me too work with, not to mention its in C# and I'm using Javascript.

Here's my coroutine:

 public function PlayOnce() : IEnumerator
     {
             // PlayState is an enum.
         playState = PlayState.PLAY;
 
         while (playState == PlayState.PLAY)
         {
             // If the currentFrameIndex (int) does not exist in the current animation array (int[])...
             if (currentFrameIndex >= currentAnimation.length)
             {
                 playState = PlayState.STOP;
             }
             else
             {
                 // Show the sprite of the current animation at currentFrameIndex
                 spriteRenderer.sprite = allSprites[currentAnimation[currentFrameIndex]];    
             }
 
             // Get the next frame to play
             GetNextFrame();
 
             yield WaitForSeconds(1f / animFrameRate);
         }
     }

And here's that GetNextFrame function:

     // Get Next Frame
     private function GetNextFrame()
     { 
             // Linear
             // AnimStyle is an enum.
         if (animStyle == AnimStyle.LINEAR)
         {
             currentFrameIndex += 1;
         }
      }

• might add more AnimStyles at some point.*

The variables are all public and set in the inspector.

I've love to know if I'm wasting my time with this method or if there is actually some kind of performance gain? Or any other kind of benefit I haven't thought of from going about it this way?

Thanks very much!

Romano