Richard,
That is true. The USPS sorting machines do not read the alpha-numeric address at all. At some sorting facilities, up to 98% of packages are sorted by machine and is not seen by a real person until it is sent to its designated area. It IS built into the barcode; however, to determine the correct barcode, the alpha-numeric address is used when printing the label (which is why sometimes an address may not be recognized).
And it is amazing how many people don't know their own address. Our office has a family that refuses to use the address that 9-1-1 issued (the Postal Service has nothing to do with establishing addresses in our rural area), so they created their own! Anyway, I hope they never need 911 because they will not be found.