There are multiple layers of assumption behind your post, not least of which is the idea that anyone would even bother to come all the way out here to strip us of natural resources. It sounds like a very industrial revolution humanity centric viewpoint. I mean, the main reason we even thought of that is because we're confined on our planet to begin with. If we could just figure out asteroid mining in a practical cost effective and not super dangerous sense (like not bringing the thing here which would 100% risk extinction level industrial accidents) we'd instantly solve most of our metals and rare earths issues. If we could find some kind of a way to get out towards the gas giants we could start burning their hydrocarbons, which more likely than not we'd have already figured out a better way of making energy than dumb shit like burning gas and coal.
Honestly our actual biggest problem right now really just boils down to clean water. You'd think this isn't such a problem on a water world but we can't drink like 99.8% of that shit.
I've posited this before but that the primary actually sensible resource which you could even find on any other world would actually just be life itself, unless you were looking for something particularly exotic which you are unlikely to find here or at least not on earth. Complex life otoh could actually turn out to be quite rare in the universe particularly as anything from Venus/Mars problems to gamma ray bursts towards the center to lack of heavier elements could make it super hard for anything much more advanced than bacteria and fungal or protozoan analogues to form and thrive, in which case I'd also likewise posit that our own future would be in xeno genetech. To give one example, NASA is using cuttlefish bone in its materials sciences division for coming up with how to structure spacecraft heat shields. The mere existence of the modern aircraft is partly the result of learning to understand how bird wings work. We took a lot of our greatest inspirations from the natural world, and typically all our more advanced stuff is sythesized from it, which means that if you're an alien civilization then it really might only be interesting and useful to go looking for genetic resources on other worlds since pretty much anything raw material you could possibly need is actually going to likely be right next to your in your own system or a neighboring one, whereas actually finding genetic resources is stumbling on billions of years worth of trial and failure engineering feats. It is possible convergent evolution would work similarly on theirs of course, but I can't really think of anything else besides tech maybe they didn't come up with yet, like maybe they never developed the silicon microchip in the way that we did but did power everything with antimatter reactors.
>all that ideology
I don't have it on here but there's this great picture of nihilists declaring morals is stupid and wrong, and then forming a conga line stabbing each other in the back saying how enlightened they are. Altruism functionally is the best and most logical course of action within nature. We likely evolved our big brains explicitly because our own teamwork was much more effective, and that all our nice shiny shit like art, culture, language, mathemetics, and resulting science and tech basically was just a happy accident resulting from that. Lone wolf hypothesis is retarded. A group of smaller, weaker things will always take down the strongest biggest thing. All the world's megapredators now need us just to make an effort not to make them go extinct through our own carelessness right now. Islam had a period of conquest like any empire, which worked for them because of uniting under a common goal, which is what the Chinese are doing and the Soviet Russians once did. Christianity has simply been one of the strongest ideologies in pushing us towards not being self serving dicks which damages our society as a whole thereby weakening the position of everyone in it. I find it ironic that all the people bitching about decline of the West then embrace will to power bullshit and completely miss the point that we live in an entirely venal, self absorbed, greedy, and callous shit tier society now with wildly declining religious rates every year and those that do claim to be religious frequently don't actually believe in all the altruistic and strength and integrity based philosophy and merely use it as another convenient mask for some dipshit kulturkampf thing. Europe got strong af through a Christian ethos, and routinely weakened itself through hypocrisy and infighting. The more a society fragments and atomizes the weaker is that society as a whole as well as the position of everybody in it.