Because you are not the main character of the universe.
You will leave behind consequences for your actions. The consequences of the actions of others gave you the world you have lived in, as will the consequences of your shape the world of the future.
There is nothing after death and we all know that, so all there's left to plan for after you die is the legacy of what you did while you were here.
Speaking for me, I value the idea that the consequences of my life wind up being more positive than negative for future generations. I also value feeling like I've changed things for the better now, and so when I have a platform or any influence I aim for that.
If you don't care about any of that, please seek counseling. The rest of us will be better off with fewer narcissists.
They meant the question showed a viewpoint that seemed to center entirely around you (also a rather libertarian thing, honestly).
‘Someone who would never build something for you’ sounds a bit like you’re expecting a tit-for-tat, I-do-this-for-you-so-you-have-to-do-something-for-me in everything, and that’s just not how societies work.
I’m curious; are you using that phrase to refer to, say, rich assholes who just take and take, or Nazi assholes that would rather cut off their own hands than build something a black person might use? Or are you using it to refer to people like severely disabled folks, or say, low-functioning autistic people, who society supports but who don’t have much capacity to ‘return the favor’?
Or are you just referring to future generations, who will be around after you’re gone?
It's metaphorically, just as building for them is a metaphor. I'm not building anything. Building for me would mean building for people like me. Be it progeny or someone who is lucky enough to be born similar to the way I am and believe similar things.
And yes, I was referring to MAGA, subtext, but doesn't have to be MAGA or political at all. It's a thought experiment.
(Also note I was stoned. As I do from time to time)