To answer the question, this service doesn't exist in any other country I've lived in -- Canada or Japan, in my case.
Even as an American I used to think this, but because I grew up in a large city where all mail collection was from a mail box at the corner of the block. It wasn't until I moved to a sprawling suburb did I have my own mailbox at the end of the driveway and I got to use that little flag thing for the first time.
In Australia, you post something by putting it in a post box, they're located in shopping areas and have specified collection times, usually daily on weekdays.
Of course, you can also go into the post office and deal with a human who will take the postage $ as needed.
These days, the number of times I've posted something can be counted in low single digits per year. Mostly dealing with government forms that need signatures because stupid reasons.
There is doorstep letter and parcel collection for less than a dollar.
Personally, I stopped trying to write such letters after a couple instances where the recipient company claimed they never received any letter from me.
Then I learned you should always send a letter with a signature to have a proof of reception, which is a bit more expensive. And then one kept charging me anyway, and still claimed the letter didn't reach the right department (after more time spent on the phone with them).
Bottom line is if a company wants to make it difficult for you to leave the relationship with them, there are tons of tricks in the books for that. Therefore I blacklist them after any sign of dishonesty.