Web developer classic: use Javascript to replace the native, working, internationally supported standard inputs with a different input mechanism that doesn't work.
(saving you a click: AZERTY has digits on the shift key, and for some reason the JS is handling raw keys rather than processed characters)
I've seen cases where it was done well, but unless you're willing to invest great engineering effort into making sure it's done well, the built-in version (which already has had a lot of engineering effort put into it) is almost always going to be better.
Former web dev here, you’re… right :-/ the only thing that angers me more than this pattern is when they decide to fuck up scrolling