> So now I'm holding firm opinion, that these high-FPS displays are marketing gimmick.

While I agree the jump from 60 -> 140 hz/fps is not as noticeable as 30 -> 60, calling everything above 60 a ”marketing gimmick” is silly. When my screen or TV falls back to 60hz for whatever reason I can notice it immediately, you don’t have to do anything else than move your mouse or scroll down a webpage.