Does “the speed of light exist”? You can’t reach the speed of light, no matter how fast you go. You can get close to the speed of light, very close, as close as you care to get if you don’t run out of energy, but to actually achieve the speed of light you’d need an infinite amount of energy.
But the speed of light does exist, it’s a limit and asymptote. Although it cannot be achieved, it exists, and is in fact a fundamental value in nature.
So too with utopia.
Utopian dreams can be dangerous. Fascists have “utopian” dreams, but this does not scare me off personally from contemplating a real utopia, one that does not emerge from killing or hate, because the idea of that utopia is inherent in the idea of progress. Can it be achieved? To an arbitrary degree yes, though there is likely a level of decreasing return on the energy put in.
And when we get 95% utopia there will still be plenty of problems for people… from the problems of the passions, rejections, thrilling love affairs, the struggle to succeed (“I will invent a space elevator!”), from political and artistic triumph and from the episodes of chaos sent by mother nature.
I want to see these dreams stated so our ideas can be clear. We believe in progress… but what is that?