- Well-known (everybody knows their zip code)
- Easily extracted (they're part of every address, no geocoding required)
- Uniform-enough (not perfect, but in most cases close)
- Granular-enough
- Contiguous-enough by travel time
Notably, the alternatives the author proposes all fail on one or more of these:
- Census units: almost nobody knows what census tract they live in, and it can be non-trivial to map from address to tract
- Spatial cells: uneven distribution of population, and arbitrary division of space (boundaries pass right through buildings), and definitely nobody knows what S2 or H3 cell they live in.
- Address: this option doesn't even make sense. Yes, you can geocode addresses, but you still need to aggregate by something.
At that point you need something like Smarty[1] to validate and parse addresses.
[0]: https://stackoverflow.com/questions/2783155/how-to-distingui...
Most sites/apps will let me override the validator, but a few won't. The most common ones that insist on using the wrong address are financial institutions that say the law requires them to have my proper physical address and therefore they go with the (incorrectly) validated version.
USPS does not do home delivery in our area, and UPS/FedEx/etc. usually figure it out given that street numbers alone uniquely identify properties in our town.
We have non-postal addresses and a lot of other mechanisms to help here. We also have contacts at the USPS and others to help fix addresses.