NVIDIA has published initial performance figures for the GeForce RTX 3070, which will arrive on October 29. The Ampere card is apparently over 60% faster than the RTX 2070 in mixed applications and around 8% more powerful than the RTX 2080 Ti.
https://www.notebookcheck.net/NVIDIA-GeForce-RTX-3070-official-performance-figures-confirm-60-advantage-over-the-RTX-2070-and-a-consistent-uplift-from-the-RTX-2080-Ti.496570.0.html
Until we know the resolutions and settings they tested at, this tells us very little. As it stands, I trust Galax to be more honest about this than Nvidia - we already know Nvidia were being *extremely* creative with their "up to 2x as fast" claims for the 3080.
My best guess: These are 4K/Ultra results, with accordingly dismal absolute frame-rates. We already know that Ampere can't hit its stride at lower resolutions and detail settings.
I'd be willing to bet that at 1080p at least - and probably also 1440p - the 3070 will struggle to outperform the 2080Ti, likely coming in second on average, hence Galax's positioning.