Into perspective
Whilst claims that he "invented" wireless transmission have been well and truly shown to be false, and no, it wasn't Hertz - he's the one who found "waves", it was David E Hughes who inadvertently discovered "Wireless" while he was studying the work of Hertz and others. At first he dismissed it as nothing but a bit of inductive coupling, so did noting with it. It was Tesla that used Hughes' findings to develop wireless transmission & reception.
But that's all by the by.
What Marconi did was commercialise it. He was the Steve Jobs of early wireless, his company was the Apple of the field. To the point that he/the company filed patents for things that others had previously invented, or were simply "prior art".