That's cool!
Androids can generate a qr code as well. I guess it's the same result but non-tech people can use it. This would be cool if it was part of KDE/GNOME or a somewhat standalone app.
I assume the webapp runs locally, right? https://ianharris.io/wifi-qr-web/ if so, it would be nice to have it stated somewhere that it's save to use (although you should probably not use a website for such things as the info is too valuable.