How come the fire stick app is different than apple?

I noticed the same app on my firetv cube does not have "on later" or clicking the network logo on the guide to get what shows are coming for that particular network...

As a user of both appletv and firetv I find it annoying that the interface is not uniform between the two... am I missing something here ?

Also I cannot see how to get the tv everywhere thing to work at all getchannels link ends up on Tubi

They are two different apps. Each feature has to be coded on Apple TV and Android TV apps separately. We are a small team, and we use Apple TV so we code the features over there first. It can take some time to translate and reimplement for Android TV.