I mean, a society devoted to enriching all humans in multiple ways will want mathematicians. A society that aims to just suck all the value it can out of a given human wouldn't need and so wouldn't have mathematicians, if the answers they give can be provided by a machine.
But the risk is of course that the benefits will not be distributed but concentrated to the elite.
Sure, I do not believe warp drive is possible, but it was of course just an example.
> [...] benefits will not be distributed but concentrated to the elite.
That's the part that's being called out as a fantasy.
I mean, a combination of political and economic factors from 1930s to 1960s forced the wealthy to return a portion of the returns of automation to the remaining working people. Then from the late 70's till now, those in power have clawed back all those gains.
Of course, any further gains from automation will go to the very wealthy unless things change.
The credible threat of communist revolutions put the fear of god into the capitalist elites. So they had to share a larger share of wealth with workers, beyond mere subsistence wages, to keep them peaceful. With the downfall of USSR, communist revolutions stopped being a credible threat, and elites clawed back productivity gains, pushing workers toward subsistence wages again.
Yes, but it won’t be work anymore, in the sense that you won’t get paid for it, if machines can do the knowledge work just as well or better. We aren’t there yet, of course, but this future seems quite possible and might not be that far off (possibly within our lifetime). So you could explore deep questions (that machines can explore much faster and more thoroughly) as a leisure activity, like sightseeing on vacation.
Or like musing while you are plowing your field by hand wondering how many of your kids will survive the coming winter.