It works directly from the Camera app in Android (at least in version 10) as well.
They said it would in the first paragraph. Too bad it doesn’t work in older Android versions, which make up the vast (vast) majority of what’s out there.
QR codes really are the wild west of identifiers: is this a serial number, a url, a business card, a wifi password?
Barcodes in general really. Yesterday I was at a hardware store where the POS terminal wanted me to enter a phone number but I’d left a cardboard box sitting on the scanner and it kept spontaneously entering the UPC code (with weird prefixes) into the phone number box.
A FRITZ!Box modem/router can print a configuration page with the WiFi info that also contains a QR code. I’m using diceware for generating a passphrase for WiFi, still easy to use by guests after explaining it actually does contain spaces ;-)