Hogwash. Humans are masters of innovation, and are highly motivated to solve problems. None of these men worked from the ground up, but built on the groundwork laid down by others (Turing especially).

The world was arguably also less complex back then, so there was plenty of low-hanging fruit to snatch in terms of information theory

Don't let the Hideo Kojima's of the world fool you into believing they did everything themselves. It's an effort of many, many who do it for the love of the craft and are content to receive no praise for it

Their adversaries had the same knowledge and resources: gears, relays, vacuum tubes. It was a fairly level playing field.

These people still exist, there just isn't the same institutional push to promote them to prominence so you don't know about them.

They were scientific revolutions ripe for the right people at the right time. These people are uncommon but they're always around, there was nothing particularly special about that generation or those few that found themselves where they did. If the events of the world wars didn't collapse civilization to the degree of the late bronze age collapse, the fall of the western roman empire, the Maya collapse, etc. then computing machinery was pretty inevitable in the span of a few decades.

You can usually make the argument that any particular scientific or engineering revolution would have happened anyway with different people nor more than 25 years or so later, at least any advancement since the mid 19th century.