AWS ELB has cross zone load balancing disabled which may cause it to be less resilient.
In AWS Console -
In Terraform -
References:
https://docs.aws.amazon.com/elasticloadbalancing/latest/classic/enable-disable-crosszone-lb.html
https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/elb#cross_zone_load_balancing