Are Replacing Rear Car Speakers Worth It?

I just replaced the two stock front speakers and head unit on my 2006 honda civic and I realized that the rear right speaker is blown. I can only hear the blown speaker when I play songs with high bass or when I turn the volume up loud. I hear from people that replacing rear speakers aren't worth it because you won't hear a difference in sound quality. Would replacing the blown speaker be worth it? Or would it be smarter to just leave it the way it is?

You can hear that the rear speaker is blown right? So you will notice the difference when you replace it with new ones that aren't blown.

Yes. Pop a pair of JBL GTO638 6.5" 3-way speakers in there and you'll be impressed with the difference. It has more cone surface than any other speaker in its size and the low-Q woofer will improve the bass response of your system significantly.