Why not use custom nginx pod rather than using Ingress nginx on Kubernetes?

Old school nginx

The past approach of the writing custom config of ngnix which basically points to the cluster-ip service of the different deployment has many limitation, one of the reason it doesn’t support sticky session and have control overs the pods as the service is attached to cluster-ip service rather the one on one pods.

Comes the hero; Ingress Nginx

ingress-nginx is a wrapper over nginx created by Kubernetes team. It directly routes the request to the POD IP:PORT rather than making the connection with Service Object.
As this comes with advantage like sticky session, controlling the routes on pods level and having broader control over the request and response modal.