> the internet was around for years before it was viable. So were computers.

The first electronic computers were purpose built to crack wartime codes [1][2]. The problem preceded the technology.

[1] https://en.wikipedia.org/wiki/Bombe

[2] https://en.wikipedia.org/wiki/Colossus_computer

A Bombe is really, really not a computer. It has more in common with a clock, it's a fantastically complicated machine, but a computer it is not. Check out a video of them being used and it's more obvious.

Colossus was a computer, although it's very unlike anything today because it isn't a stored programme computer. So it's more like one of those LCD watch games from the 1980s, it could do something else than what it's doing now, but only by literally taking it to pieces and rewiring it.

But your main point is spot on. In the mid 1940s several machines including Colossus are built mostly by military groups and these fulfill different criteria for bring a "computer" as we'd understand it. But by 1950 companies are already selling these new "computers" for commercial use. The US Federal Government bought several in 1951.

Segway has been around for years and still isn't viable for more than tour rentals.

Just because it's a technology doesn't guarantee it will be as successful as other technologies.