Earlier quoted context omitted.
Yes, I'm rather glad I haven't had to deal with localizing decimal inputs, just displaying them. I have had to deal with localizing date inputs though. Ugh.
Why is this "ugh"? The way I see it, we're building software for users, and we try to make it useful for them. And part of that is trying to come up with a pleasing and easy to understand design language. And another part of it is catering to different cultures and languages. For example, afaik, the standard way Chinese dates are written is something like "2020Y02M28D" but with the Chinese characters (words) for year…
But it goes beyond "this is what they do". Users tend to do a wide range of things when entering dates and you kinda have to guess what they mean. Throw in guessing what localization should be used (it's not always clear) on top of that fuzzy system and it can become a frustrating experience for everyone involved.