> Nothing I've had a hand in building / maintaining has "survived" for more than ~7 years.
The companies? The websites? Google, for example, has been in existence since 1998. If you're working on a farm, the crops don't live longer than a year. The livestock longer than that, but probably not decades - my (limited) understanding is that most cows are slaughtered around age 2 or 3. But the farm itself can, in certain circumstances, last for generations.
If you're talking houses, sure, solid walls can last decades, centuries, millennia even (cf the Pyramids). However, I think this is because stone is particularly durable. Roofs, windows, doors, anything that isn't made of really good masonry will tend to decay much quicker than that. Even states like the Roman Republic and Empire (which had probably a good ~2000 year run if we count from 509BC to the fall of Constantinople in 1453) will eventually crumble and fall.
Now a tech company is a newer type of institution than a farm, but some of them are quite old - GE was founded in 1892. IBM was founded in 1911. We can also take Bell telephone and Standard Oil, both of whom were broken up by anti-trust cases, but whose descendants still live on today, as other examples of tech companies that have had lifespans similar to or greater than houses or farms.
Of course, I understand that "I built some software/racked some servers for a company 20 years ago and they're still business" isn't the same as "I put the bricks in that wall twenty years ago and the house is still there". So I agree that the individual artifacts we create in the tech industry are somewhat fleeting, compared to things made of metal and stone, even if, compared to things like music or other performing arts, where the song disappears the minute you stop playing, software running on computers is relatively lasting. And artifacts created with software, while they are a relatively new thing, may prove quite durable. Films made with Final Cut, or songs made with Pro Tools, or heck, even video games like Doom, may prove to outlast every house that you ever worked on. It's possible that 200 years from now, people will still be watching YouTube videos made today, even if, in a Ship of Theseus like fashion, every line of code and every server that YouTube is currently using has been replaced since then.