Reference Mode with Sidecar
This last one isn’t something that most Intel Mac users will likely miss, but Ventura’s most interesting new Sidecar enhancement will also require an Apple Silicon chip.
Reference Mode with Sidecar lets you use an iPad Pro as a secondary reference display for your Mac, but it only works with a single model of iPad right now: the M1 12.9-inch iPad Pro with Apple’s Liquid Retina XDR display.
In other words, you not only need an M1 or later chip in your Mac, but you also need one in the corresponding iPad, and that iPad has to have Apple’s top-of-the-line display technology.
It’s a niche feature, to be sure, as it’s primarily intended for professional workflows where it’s necessary to do extremely accurate color grading and compositing. It’s likely anybody who needs this will either have an Apple Silicon Mac or already have better solutions in place, such as a Mac Pro paired with a Pro Display XDR.