when's it worth it to implement a service mesh?

Hey everyone, I'm starting to check out service meshes, things like Istio and Linkerd, for our microservices. We're hitting some snags with observability and making sure communication between services is reliable as we get bigger. I'm really curious to hear from people who have actually started using a service mesh. What made you finally decide to go for it? Was it worth the extra hassle, or did you find that simpler options did the job just as well? I'm looking for honest opinions and advice based on actual experience.