Anyone scaling ArgoCD across multiple clusters?

I’ve been using ArgoCD with GitHub Actions for GitOps, and it worked well in the beginning. But once I started managing multiple clusters, it got more complicated:

- Syncs slowed down

- Had to spin up separate ArgoCD instances

- CI/CD felt disconnected from the GitOps flow

Would like to hear how others have approached GitOps at scale. Did you stick with Argo and layer on tooling? Or move to something like Flux or a custom setup? Any lessons learned are welcome.