No one made this claim.
The claim is Ampere's very high FP32 throughput may never result in significantly higher performance in future games because the architecture isn't designed to use all that throughput in games anyway (e.g. it can't really do 30 TFLOPs unless the TMUs, ROPs, geometry processors, etc. are unused).
And just like Vega 10 was a chip developed to compete in too many market segments (gaming + productivity + compute), Ampere / GA102 might have also been developed to increase nvidia's competitiveness on non-CUDA compute workloads, which was apparently nothing to right home about compared to Vega.
Ampere is using all of these FP32 flops. Thats the reason why a RTX3080 is 60%+ faster than a 2080S and 30%+ faster than a 2080TI. Crunching through compute workload to offset other limitations.