Is this bushing cooked?

It’s a tear, and the chunk is kind of loose. I already replaced it, but didn’t throw it away. I didn’t notice any issue when riding apart from the squeeking, but that may be because it’s been a few months since I grated soap in between the trucks and cup washers. I also didn’t want to ride it until it’s completely destroyed. So it’s also a general question: when it’s a good time to replace bushings?