This is what I don't really understand about modern-day rich / famous people; they'll build big houses and yachts, and some governments even build government se

This is what I don't really understand about modern-day rich / famous people; they'll build big houses and yachts, and some governments even build government seats and palaces which might be preserved for the ages. But it doesn't feel like they're building "monuments" per se. Then again, survivorship / selection bias like you said; we don't yet know what the Wonders of the World built today will be in 2000-4000 years, because we don't know what will remain or what will be considered significant. I mean there's huge skyscrapers, ostentatious buildings built in the richer cities. There's a giant clock in Mecca, the Venetian and Grand Lisboa in Maccau, the New Century Global Complex in China, etc. But few or none built to just exist, like the pyramids that were sealed off. After solving world hunger etc, if I were stupidly rich, I'd have a monument built. Sealed off containing the world's knowledge in redundant and multiple mediums. And with a visitor center / museum because people will be curious, of course.