notifications are just STILL too unreliable

I have convinced all my closest friends to migrate und even made sure that they're on auto update and on no battery saving bs.

but still, from some people i don't get reliable received with 2 checkmarks notifications while every whatsapp message is getting through.

like this one friend on a samsung.

last resort would be to install that one store without google play services but who says that apk isn't even less reliable?

but i have to say, i've never had any issues with iphone users.

and i receive my messages fine, i guess. never had any complaints of delays. i'm on a pixel with grapheneos.

i am aware of this website dontkillmyapps and how every phone brands makes its own rules. but that just can't be the whole reason right? how is whatsapp able to bypass all these random battery restrictions and signal isn't?