A question about mailboxes

This is not exactly a Montreal question, but I don’t know where else to post about it.

In my neighbourhood, mailboxes are all about the same size. Mine is about 5 inches wide, designed to accommodate a standard #10 business envelope with a little clearance. So are almost all the ones I’ve noticed around here (since thinking about this matter).

A lot of the mail I still get comes in bigger envelopes now. My RQ tax assessment and my Visa bill both arrived today in envelopes 6 inches wide. I knew I had mail just now because I could hear the letter carrier struggling to put the envelopes into a mailbox not wide enough for them.

What, I am asking, was the point of shifting from an envelope meant for letter-size paper folded twice to an envelope meant for folding it once? You don’t save paper. You only create a chronic minor hassle on the receiver’s end for many people, and no doubt an ongoing problem for letter carriers trying to deliver mail without tearing or damaging it.

Is there some benefit to the bigger envelopes that I’m not getting?

Update: I guess this is just me. Nobody else minds having their mail necessarily bent or folded? Everyone else has a huge mailbox?