The previous capabilities of Quicktime, Airport Utility, Disk Utility, and Pages did not come back. The "new" Quicktime was introduced 8 years ago.

The pattern we've seen is Apple decides to re-write a utility because reasons. The new version comes out as part of a major OS release. Then nothing further happens.

The exceptions are the major apps like iTunes, Safari, iMovie, and iPhoto. Also the "discoveryd" re-write is extremely noteworthy in that it was fully withdrawn and replaced by its predecessor.

The loss of codec support in Quicktime was probably related to improving battery life by forcing use of H264, which is hardware accelerated.

Whether this is wise is a different question.

But no you're right, there is a definite pattern of feature loss going back to iMovie HD 5. I'm still using Pages '09 because it does what I want and feels snappier.

Also the entirety of Quicktime Pro, which enabled full transcoding control was lost.

True. Except for the old "Dial via Bluetooth" feature. It used to be a Service accessible system-wide. You could highlight any numbers and right/command-click to dial a paired phone. This disappeared when the iPhone was first released, and never returned.

There is a call with iPhone feature as part of the Handoff functionality. So can then conduct the call via your Mac or switch to your phone.

So in typical fashion a redesign with a more Apple centric feature set.

Not via Bluetooth, but you can make calls via iCloud-paired iPhone, either using the phone as a relay, or using WiFi calling on supported carriers using a similar workflow.

I would argue the exact opposite is true. Can you cite examples?