This comes off as extremely disingenuous. We aren't unable to inhabit Antarctica for the long term, we just aren't interested in doing so. We don't have much left to learn about living in space from living in Antarctica that we haven't already learned from the people who live in the various other parts of the world which do have permanent settlements and experience extreme cold for large parts of the year. Thus there is no real point to doing much else there in terms of human spaceflight.

Just like how America hasn't outright been unable to develop the means to go to the Moon again for the past 60 years, it just has had other priorities.

In fact, following your logic, Artemis also should be cancelled until we've spent the arbitrary duration of 100 years sitting around in Antarctica just to prove that we can do it.

An additional point being missed is that when we started talking about going to the Moon the first time around, we didn't really know how to do it, we sent out several impactors just to learn enough about the surface to decide where to go. By setting that goal we gathered data for the purpose and eventually managed to do it. Similarly, there will never be a time where we are 'ready' to go to Mars or any other distant celestial body if we just keep waiting for arbitrary requirements to be met. Right now it's living in Antarctica for 100 years, then it'll be something more ridiculous and arbitrary like maintaining an artificial atmosphere for 1000 years.

Right now we're in a similar phase for Mars as we were for the Moon in the early days of Apollo. We've been studying the surface for decades now, have got rovers storing away reference samples and testing oxygen production, we've even been testing how much mileage we can get with less conservative choices in hardware (eg Ingenuity's processor being much more modern than Perseverance's and Perseverance's landing footage being mostly off-the-shelf industrial cameras made possible by the more modern coprocessors being used to compress the video onboard before transmission).

A stated goal of Artemis is to use the Moon as a step to Mars, which it's turning out to be given that the only vehicle remotely capable of making the trip survivable is on the critical path of establishing a long-term presence on the Lunar surface. Everything that has to be developed for missions to Mars will end up tracing back to something tested or learned from Artemis, just as many aspects of Artemis are based on things tested on, developed for or learned from the ISS.