How come more apps don’t sync notifications?

[contacos]

For example, I have WhatsApp installed on two iPhones and as soon as I open WhatsApp on one device, the missed notification disappears from my other iPhone (great!) However Reddit or Instagram for example don’t seem to behave the same way. If I check a notification on device A, it remains on device B, including the annoying notification badge on the App icon.

Is it a restriction from Apple (only texting apps allowed) or do most devs simply not bother to implement this functionality?

I wish this was done by the system. It’s great

 

[NoBoMac]

It's on the dev end. Apple provides a framework to do it but up to the dev to setup their own backend to actually handle the workload.

https://forums.macrumors.com/threads/sync-notification-between-ipad-and-iphone.1484261/post-31139513