I believe it was removed in big part due to being a relatively big energy drain. With that in mind, I don’t believe it was a bad decision, even though I liked the feature as well. (Though probably with additional R&D on the topic, it could have been improved)
And, IIRC, 3D Touch was also technologically infeasible to implement on iPad. That sharply limited what they could do with it, since it would never be available on all iOS devices.
