Android Background Service – Why Is Whatsapp Working Differently?

Deleting Google Play Services is sad when it comes to notifications. A lot of apps use Google Play Services to handle notifications. For example Discord notifications don't work at all.

But in other cases like Telegram, when the app realizes that is living on a phone without Google Play Service, then it starts a service in the background, telling you that "In order to have a background service we have to display this permanent notification".

My question is: why Whatsapp is working differently? (Whatsapp doesn't need a permanente notification, but messages notifications are working fine)