I work in the field and I will have to disagree - 20 years ago nobody serious would have claimed we can build a quantum computer in 10 years. There are very clear levels we need to reach to have something useful (in terms of lifetime of the qubits and number of connected qubits) and there has been extremely clear upward slope on both of those measures over the last 15 years. Extrapolating optimistically from them in 5 years we will have quantum chemistry simulators. Extrapolating pessimistically, it will take 20 or so years.

This is simply not true.

I'm not talking about the pop science articles you read who find the most outlandish quote they can find. (There are plenty of those now that say 1-3 years.) I'm talking about what the actual typical practitioner says.

Relevant xkcd:

https://xkcd.com/678/

That's because with new developments that do get achieved in predicted timelines, the predictions don't get mention because it's only unsurprising ordinary news. Whereas with tantalizing but out of reach technologies, we get repeated "are we there yet" articles, and skepticism makes for more popular journalism. It's a combination of selection bias and the availability heuristic.

Really? How about mapping the human genome?