Well that estimate is better then what my 1990s plasma physics prof said - Fusion power is 20 years away! And always will be
The younger guys use longer timeframes.
One can roughly approximate the age of the person based on the amount of time they claim is needed.
Younger guys tend to use dates farther out in the future. They have other things they want to do with their private lives and aren't so ready to pack bags and switch jobs. Plus some of them haven't fully realized that what the older guys tell them is BS.