Apple Watch: It's a smart watch, they didn't invent the category, but it's a novel form-factor, instantly recognizable. The operating system is also highly distinct from others. You'd never confuse an Apple Watch for anything but an Apple Watch. Some of the Android based ones are going out of their way to look like non-smart watches. At least Motorola has their own design language here.
F.lux: Significant functional overlap but these sorts of tools have been around since the 1990s. It's not like F.lux invented this, they just popularized it. Maybe it was a dick move on Apple's part, or maybe it was just a thing they thought should be core to their product.
When Microsoft wanted to add faxing functionality to Windows they could have bought WinFax, but they instead made their own thing. Is this stealing?
I think your definition of stealing and copying is extremely loose, to the point where the term has lost all meaning.
Your comments use words similar to mine like "the" and "a". Are you stealing my words?
Their ideal product entry point is when consumers are familiar with the product but are unhappy with the current offerings because they lack the right contextual fit.
Maybe if you have a specific example here of where Apple's flagrantly copied something like Xiaomi has we can talk specifics.