While the Snapdragon 730 and 730G (a 730 "for the elite gamer") are both direct successors to the Snapdragon 710 mobile platform, the new Qualcomm Snapdragon 665 comes as the only heir of the Snapdragon 660. The first devices to use these three new mobile platforms will hit the market this summer.
https://www.notebookcheck.net/Snapdragon-730-730G-and-665-Qualcomm-unveils-three-mobile-processors-for-mid-range-and-high-end-devices.416096.0.html
Now where's the 675 in that lineup?.. :-|
Coming soon, I guess...
Twice as fast, for the 710, sounds faster than the 855...
... that's what Qualcomm is saying. In most cases, talking about certain optimized scenarios, mostly involving AI.