As an outsider, the fact that cross-device stuff just works in apple's ecosystem is probably the biggest thing I'm jealous of. It's crazy that something as simple as screen casting is still hit or miss when it comes to (android / linux) <-> (web os / chromecast / fire stick)
I just bought binding of Isaac on Apple Arcade for my iPad, a very good surprise was not that the purchase is valid for my Apple TV and iPhone, but that the saves are synced, even in mid session!