You are looking at the wrong figures, the only thing the 1080 Ti is cooler in is Furmark which does not count.
The different is tiny but after all the publicity about the 1080 Ti having an improved cooler I was expecting better.
I think the thing is with FE profiles, the cards all go to 83 degrees +/- a few degrees and maintain a boost to stay within those temps. So seeing 84/85 degrees IMO is kind of meaningless as they do fluctuate to those temps at times, just depends when they took the measurement.
I think it will help even if tiny to some extent as the 1080Ti must be boosting higher in normal use to outperform the Titan XP in most of those Benchmarks.
Though yes, no doubt there is some marketing hype going on also, they pegged the 1080 at 220watts in that scenario (serious overclock) and likewise the 1080Ti at 220w (so an underclock) to make numbers look better for example.