It also raises the question of how electric something has to be to not work. Flash photography works, so capacitors are seemingly okay. Even a simple one-wire telegraph system would be an improvement on owls.
Come to think of it, we come across actual magical radio broadcasts at several points. Even magical password-protection of same. Why the hell do they still use owls?
Because delivery of packages to rural areas is terribly unprofitable.
Certain things need to be socialized in order to keep a country connected and enable development.
Without things like the post office, rural electrification, and the Eisenhower Interstate system, vast swatches of the US would have zero economic output.
Context is important.
It's a fair question though - anecdotally, the two main uses for the postal service nowadays (in countries with internet access) are package deliveries and unsolicited marketing (possibly print subscriptions factor in).
To my mind, the unique advantage of the Muggle postal service for personal communications, apart from the globally federated physical distribution network - the one that would make me very hesitant to scrap it - is the difficulty of conducting mass surveillance on it.
It does? But yes, these things are glossed over quite a bit, which is also odd since there are enough wizards that grew up as muggles and should have a fairly good idea about what technology can do, and would miss tech they'd have to leave behind ((EDIT: in a modern version) no smartphones, no internet would be quite a jump for kids used to them)
Any suggestions for fantasy that does it better? I can think of Charlie Stross' The Laundry Files (where technology is actively used to harness the power of the paranormal), the Harry Dresden series and the Night Watch series (which shows older wizards struggling with technology, younger ones actively using it, and at one point an army of humans with magical artifacts posing quite a challenge)
As for story suggestions - well, I don't read a lot of fantasy, but the "fanfiction" Harry Potter and the Methods of Rationality (by LessWrong's Eliezer Yudkowsky) is a deeply amusing take on what havoc might have been wreaked in the Harry Potter universe by someone who, finding themselves in it, applies the scientific method. (If that's not enough to pique your interest, at one point in the story Harry explores the possibility of using a time-turner to deterministically solve NP-hard problems through the forced creation of stable time loops.)
Another good story is Sam Hughes' "Ra", where magic is literally a field of scientific research and engineering. It scratches the same itch as Methods of Rationality (scientific deconstruction of magic), but in a universe built for that purpose. It's awesome.
In the Dresden Files books, it's a sliding scale and the titular Harry Dresden drives an old VW Beetle because it's primitive enough to still (mostly) function in the presence of magic.