One rebuttal to that is that with the benefit of hindsight, to a first approximation zero percent of the code I've written in my career turned out to be "of any significance" really.
Most code I wrote over my career got pretty decent use and produced value for customers. Some was used by millions of people. What I work on today is used by thousands. It's important that it is of reasonable quality with less bugs, decent performance, functionality users are looking for etc.
A lot of code makes a difference but I guess there's a lot that doesn't?
Same. That line about "your legacy is your family and friends" hit hard.
I've been coding professionally for >30 years. I don't think any of my code has survived 5 years in production.
I don't think code quality affected that at all - I know the really, really, shitty code I wrote when learning OOP in the 90's survived for a looong time, while the amazing code I wrote for a startup 2018-2021 died with it.