I think it’s also worth bearing in mind that vega at 100% fan speed is not indicative of true performance as it’s simply unplayable so I will take ‘suicide run’ performance figures with a pinch of salt too.
Who said anything about 100% fan speed? If you look at the comparable Vega 64 in UK it's the £420 Nitro, which most assuredly doesn't need anywhere near 100% fan speed for even high OCs. Here: https://www.tomshardware.com/reviews/sapphire-rx-vega-64-nitro,5388-8.html
If anything, AMD's cards always perform better when adjusted for temperature because they don't throttle as soon as Nvidia's. Even more so in Polaris' case.
While that's great for the Vega 64, this doesn't look great for the VII to be honest. It's supposedly ~30% better than the Vega 64. 83*1.3=107.9, that puts it level with the 1080 Ti and 10% behind the 2080 that it's supposed to compete with.
Like I said before, those aren't indicative numbers, as TPU is a shoddy site, and more importantly the numbers given by AMD for V64 are from the LC edition, which is above any 2070 anyway. So rest assured, Radeon 7 will at best be no worse than a 2080, though likely better especially if we look at the tweaks still possible for AMD cards which for Nvidia are locked away.