Deleting load balancer from console is easy. Just click on delete icon and wait for the load balancer to disappear.
Is there similar gcloud command to delete load balancer (cascade delete all related frontend, backend, url-map, health check etc. )?
GCP Documents explain how to setup various load balancers but none of them cover how to clean up
There is no single gcloud command to wipe out a loadbalancer. You'll need to delete its constituent parts, one at a time.
These parts are:
Backendgcloud compute backend-services delete [BACKEND_SERVICE]
gcloud compute target-${PROTOCOL}-proxies delete [TARGET_PROXY]
gcloud compute forwarding-rules delete [FORWARDING_RULE]
gcloud compute addresses delete [IP_ADDRESS]
gcloud compute health-checks delete [HEALTH_CHECK]
gcloud compute url-maps delete [URL_MAP]
Depending on your needs, you may or may not want to actually delete your static IPs and health checks, or even have any URL maps to delete.