You think putting a pressure sensitive display on a phone is as groundbreaking as Apple wants you to believe it is?
Actually yes. Putting a pressure sensitive display on a mass-market mobile device with the necessary coding, API, and UI to make to usable and useful is groundbreaking and an engineering feat. Heck I'd call it that and I don't even think Apple is fully gotten it right - for instance, I agree with others that to improve its usability there should be a visual/haptic/some kind of indication that there is a 3D touch interaction available (even better would be to indicate how many layers of force there are). I have no idea how to do this btw (without being clunky), but someone needs to figure it out.
Remember Apple develops hardware/software for large-scale consumer use, especially in its iPhones, and the engineering difficulties are entirely different than for what we often think of as engineering R&D. Again, to give an example, Macrumors has several articles on the fact that 3D touch will not come to the iPad and will not change for the next iPhone because the technology isn't there yet do so. That doesn't mean it is physically impossible to create an iPad with a pressure sensitive display. Of course, one could put a (great) pressure-sensitive display on an iPad right now, heck even years ago I'm sure it was possible. But they can't do it in a manufacturing process meant to churn out millions of them with the high yield, good quality, and reasonable costs necessary for a consumer device (even one with high margins).
That's where the breakthrough comes in. Now that doesn't mean Apple is alone in doing this or that the stereotypical Apple fan's response to the rumors that Samsung employing it is reasonable (though Huawei deserved the universal condemnation it received from reviewers for half-baking their solution just to announce it first). I'm sure that the company that is developing the technology Samsung is using has been developing their solution for awhile and would've done so without Apple's progress in the field (though knowing Apple was working on force-sensitive capacitive displays probably encouraged them to work that much harder

) - i.e. they didn't look at the 6S and decide 3 months ago to develop their hardware. To further qualify my qualification: Note this doesn't mean it will be good or bad or Samsung's UI and API will be good/bad used/ignored by developers or that Samsung themselves aren't encouraged to use it because Apple did it. It's just that engineering research at all levels from basic science to R&D to manufacturing takes awhile, not everything is done because of copying, and finally that the last stage of research is just as necessary as the preceding stages for a product to reach us, the consumer.
In summary: Engineering research for consumer devices can still be considered breakthroughs without coming out of nowhere with no development history anywhere else. The latter is not typically the kind of R&D Apple does (well sometimes yes, but not often). However, the former is still very valuable and important to recognize and applaud.