Nah, the thing is there’s different engineering demands on those locations, and a legal issue for Antarctica as well. - shifting ice moving at different rates

Nah, the thing is there’s different engineering demands on those locations, and a legal issue for Antarctica as well. - shifting ice moving at different rates on a the ice cap and even more so on glaciers, and legally we consider it a protected environment we explicitly don’t want to colonise - the oceans is corrosive, plant and animal life is everywhere from biofilms to barnacles your stuff is going to become covered and anything left open or closed for too long without extensive cleaning and maintenance will become a slightly different shape than you think it is… and that’s a problem due to the crushing pressure required to make use of all but the shallowest waters, so shallow there’s not even really that much of them… otherwise your past 100m and ten atmospheres of pressure and it’s not only challenging it’s make mistake and die instantly challenging, you go deeper to get more “land area” and those extra atmospheres will turn a pinhole leak into a knife made of water even if the structure remains intact while filling with water… it’s not a great place to be when things go wrong… short of insane over engineering things like giant thick steel spheres (thickness obviously depending on depth) we would be also dealing with breathing pressurised atmosphere to minimise the pressure differential between inside and out… it’s just all around a lot harder to utilise most of the earth’s ocean floor. - the worst the moon can throw at us is radiation, a 1 atmosphere “pushing out” pressure differential and very nasty dust… all of which have simple enough engineering solutions that we routinely build equipment using on earth, clean room style “high” pressure (not really that high just enough to dislodge stuff) blowdown entry systems (which could be way more powerful if your in a spacesuit… would easily handle the dust and worst case use the decontamination shower approach, we found ice, there’s water, use it to avoid the bad dust getting in. As for the radiation we’re exposed to a bit of it normally, there’s a little less in the magnetotail and earth shields it a bit and between limiting surface time per week/month/year and digging habitats underground you get well below safe limits… the digging also simplifies the pressure differential and even without it, we’ve been making spaceships for decades and industrial pressure vessels that can take greater pressure differential for over a century… - mars has less of a pressure differential, less solar radiation due to square cube law, and peroxide rich soils. Well chemistry is a pain but industrial chemicals get made and we know how to manage cleaning processes and decontamination for anything I’ve seen listed in the Martian regolith at least. The radiation can be solved just like on the moon the same thing goes for the pressure differential. It’s not a matter of technology, it’s been a matter of cost per ton to low earth orbit since about the 1970s… or the 2000s when we finally got our heads around some of the non-biological “closed loop” O2/CO2/H20 life support technologies, capturing the CO2 , breaking it to CH4, getting back the O2, getting H2 and 2 O2s from the H2O and balancing all this with systems to vent or otherwise utilise excess H2 or CH4, did take us a bit longer… but with a low enough cost per ton it could have been done earlier, logistics are logistics, be it fresh fruit products on a train from Florida to NYC or the fleets of trucks that bring food into inner city London, we live in a world where a significant portion of the population are no where close to self sufficient and are reliant on the operation of logistical chains that bring them what they need to live without having to move closer to food producing regions. Space would be no different, 3-7 day transits for quite a lot of fresh produce to stores are tolerable if less than ideal (faster is always better) and that’s perfect doable to the moon, mars would need us to step up our agricultural game a bit but if we ship up soil by the ton and we have water, we can make a greenhouse in a box and the plans will be fine anywhere, and some fresh produce would even be able to make that sort of trip, and industry on the moon could build things like long magnetic track launchers that could get cargo up to velocities where the transit to mars is weeks if you built the launched cargo units so you could give them enough fuel to decelerate in time (at that speed your not aerobreaking in mars’ atmosphere that’s for sure)