A Mars colony is something humanity should start thinking seriously about once we successfully run a production-grade lunar colony for about a decade-- long enough to recognize and tackle the worst bugs.
To survive planetary disaster? Well 1) Mars is already worse than most imaginable post-disaster Earths would likely be, and 2) you could build a couple highly-survivable emergency bunker-habitats and pay people to live in them (in shifts, say, so there are always enough inside to ensure survival but they're not stuck in there full time) for, surely, less money than Martian colony establishment & maintenance would cost. You might still screw it up and they might not succeed if things really got that bad, but I'd bet their odds are better than any Martian colony we're likely to manage to put up in the next 100 years.
We could call these bunker-habitats "vaults", maybe. Then proceed to raise some capital for our startup and eventually call it "Vault-Tec"[0].
> You might still screw it up and they might not succeed if things really got that bad, but I'd bet their odds are better than any Martian colony we're likely to manage to put up in the next 100 years.
We could further fund it by conducting various sociological experiments. What could go wrong?[1]
I think on the architectural & engineering side developing structures for Mars would provide immense progress in understanding sustainability for life on earth or elsewhere. This has applications for doomsday scenarios if you care about that as well as just general efficiency and sustainability of structures.
Likewise I think Mars has benefit as a potential launch point for space travel as it has an abundance of fuel and a significantly lighter gravity well.
Another part is the whole "necessity is the mother of invention" aspect. There is no quicker way to progress than doing. Yes it may be horribly dangerous but trial by fire has been repeatedly shown as a very effective way of exploring the unknown.
Mars has dust fine enough to be effectively aerosolised, and the low pressure makes removing it a bit tricky.
NASA has some ideas. https://www.nasa.gov/feature/kennedy-scientists-developing-t...
But yeah, we probably wouldn't put a base those places, not initially. Though I wonder if a volcano base would tell us more about the planet's interior...and its fairly flat including lots of high walls to protect against winds/storms?
https://www.esa.int/Our_Activities/Space_Science/Mars_Expres...
We haven't really used spin gravity in practice yet, so there are technical problems to solve there.