Permanent, independent residence apart from Earth strikes me as a similar challenge.
At some point you'd think people would get tired of being wrong.
Many people suspected that the airplane naysayers were wrong because heavier than air flight was already possible and the only problem was sustaining it via mechanical means and carrying a human. There were numerous examples, from falling leaves to birds to children's gliders.
I reckon powered heavier-than-air flight was "proved" possible the second someone observed a bird of prey or scavenger carrying close in mass to itself.
There is no example of a generation ship. Earth doesn't count. I think they won't work because there has been no mechanism yet built that has lasted for the amount of time a generation ship will need it to last. Then you get into a mass death spiral of spare parts, raw materials, machines needed to create spares out of raw materials once the spares run out, recycling, storage of bulk raw materials, and the fuel needed to move all of that mass. Even the oldest currently-operating non-trivial mechanical devices, probably clocks that have been installed in continually-operating cathedrals, have had TONS of external inputs in the form of lubricants, wood, and metals for replacement parts over the centuries they've been operating.
Not even granite boulders "last" for tens of thousands of years. They weather and chip and change over timespans that long and are not the same as when they were formed. Space is not as hostile in some ways as the earth's environment but it is more hostile in other ways-- especially when you start approaching even a small fraction of the speed of light. People think a fusion reactor can be constructed will last for 50,000 years?
"Oh just use robots and to keep the robots from breaking down they'll be organic self-replicating robots and everything will be recycled in a closed loop even though it is impossible (literally and actually absolutely impossible) to construct a pressure vessel (like, it's atomically impossible it doesn't matter what material you use or how thick you make it) that won't either leak or absorb (seriously, even if you made it out of an exotic element not yet discovered that is denser by orders of magnitude than anything we can even dream of and install a magnetic containment field it WILL leak) the atmosphere to a noticeable degree over tens of thousands of years.
So then people come up with hand-waving solutions to those problems that are the equivalent to "oh they'll just use AI/the blockchain/hyperdrive".
Tell you what.
Once industrialized society exists for the amount of time it will take to get to an inhabitable star (so NOT Proxima Centauri) I'll say "you know what if we can last that long it might be worth figuring out the mass death spiral problem". We'll see if we last that long.
Until then?
Impossible.
There are no cohorts of commuters using there bicycle blimps or personal jetpacks to cross the skyways of Paris, for example.