For me it’s Herr Heinrich Rudolf H.
When asked about the importance of an experiment he had performed, Herr Heinrich said…
“It is of no use whatsoever […] this is just an experiment that proves Maestro Maxwell was right — we just have these mysterious electromagnetic waves that we cannot see with the naked eye. But they are there.”
When asked what the practical application of this was, he said…
“Nothing, I guess”
Herr Heinrich Rudolf Hertz had just invented the radio (*).
To say that the emission and detection of radio-waves have in some small way shaped modern society sincefirst made his invention — or rather: confirmed the validity of in real life — is to re-define the concept of “understatement”.
And I am certain that — had we time-lifted Herr Hertz from this little experiment in 1886 to today — and shown him that, is a direct consequence of him and his experiment, he would have been most confused, or in the very least astounded, and then smacked his own forehead in an epic facepalm for giving such a terminally unimaginative answer.
(*) Of sorts… it was the first device ever made to generate and detect radio waves. It was not a practical device by any means, but it was the first specifically made to transmit and detect radio-waves.