This can also cause delivery failures the other way around - a friend in Germany once sent me a package but didn't bother writing the apartment number on it because she assumed the postman would use my name to find the right box. Instead it got sent right back to Germany. (Austrian bureaucracy is just as unforgiving as German, they just have different rules to follow...)
3 days later our postie knocked on our door and asked if this parcel was for us!
We don't live in a big city but still it is a town of 20,000 so not that rural where everyone knows you, so I was impressed that they cared enough to try to figure out the address. Granted the post code narrows the search down.
I am certain had it been shipped the other way the post office in Norway would have rejected it immediately for not being 100% by-the-book.
BTW in Scotland at least, during the Christmas period, it is customary to leave a Christmas card for the postie outside with a small bank note in it. An easy way to say thank you for their efforts and to ensure that the postie will remember your name even better next time ;)
Also, while I agree with you that in this case (having a full postcode as well as name) it would have likely been an easy task for the local postie, Royal Mail do actually have a small team* of people who work in figuring out more tricky ones, so if a local person can't work it out for being on their beat it can be sent to the "address detectives" (great title!) to try to solve.
This is a great example of that from a year or two ago, including a few other similar stories at the end: https://www.theguardian.com/uk-news/2022/jan/07/lives-across...
* My knowledge is both 20 years out of date and fuzzy in my memory, so I've no clue how big a team it is nor if there's enough confusingly-addressed items to need anyone working on it full time, or if it's just one aspect in a wider set of responsibilities that a team does when needed.