> For example, Macs have long had the "Network Link Conditioner" tool as a free utility included with the Additional Tools for Xcode package, which then allows simulating configurable bandwidth, latency, and packet loss.

Well, I sure wish Apple would make use of that functionality themselves once in a while.

It's frustratingly impossible to enqueue an iMessage message while out of signal and have it be automatically delivered once back in cell coverage. Bizarrely WhatsApp, a third-party application (with all the background execution restrictions that go with that), manages to do just that!