I'll go against the grain here, but 3D Touch was the most overhyped and underdelivered feature in years. I'm constantly pressing either too hard or soft, or getting mispresses when I'm not even trying to use the damn feature.
Yup. It's a badly conceived idea that only appeals to power users and just makes the UI too complicated for the average person. It's a weirdly un-Apple idea.
Given the new devices coming out not supporting it and making it unattractive to devs I can see it being quietly dropped entirely in the next three years. I would make a reasonable bet that there'll be an on-off toggle in iOS10 for it, and that'll default to "off" in iOS11.