Nvidia turns up the AI heat with 1,200W Blackwell GPUs
theregister.com
theregister.com
It depends what you mean by "high demand". It's extremely unlikely you'll be able to buy one for less than $20k.
More discussion: https://news.ycombinator.com/item?id=39749646
The list of applications for which FP64 is required is huge, but they are less known because they belong to scientific/technical computing. Any design engineer would use such applications, but most programmers and non-professionals would not be familiar with them.
https://www-users.cse.umn.edu/~arnold/disasters/patriot.html