He is right when comparing next gen to last gen, since 1 Tflop next gen will give you much more than last gen. He also is right when comparing across to different architectures. However, we are comparing two GPUs that will both be based on Navi, so will function almost exactly alike. In that case, Tflops should actually mean something.
I would say that ceteris paribus (meaning all else is the same between the 2 CPUs) then of course 12 or 14 TFlops would mean more actual power than 10 TFlops.
To marketing thought even if the 10Tflop GPU of one console is better overall in real world than the 14Tflop of the other one. The one with 14 will make the adds saying they are the most powerfull and have 40% more processing power than the other. So even on the Tlop both will try to have as much as possible.
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"
Azzanation: "PS5 wouldn't sold out at launch without scalpers."