C#'s "ToUpper" takes an optional CultureInfo argument if you want to play around with how to treat different languages. Again, solved problem decades ago.

This is not a locale issue, it's a Unicode version issue. Which hightlights another problem with adding this to the base standard library.

That was only adopted in Germany like 7 years ago!

Well languages and conventions change. The € sign was added not that long ago and it was somewhat painful. The Chinese language uses a single character to refer to chemical elements so when IUPAC names new elements they will invent new characters. Etc.

Does unicode have space set aside for those new symbols to slot into? I know it's very rare, but it could get messy.

Unicode is already messy. Chinese characters especially so due to han unificiation.

Isn't uppercase for ß just ß - i.e. it's its own uppercase character?

there shouldn’t be an uppercase version of ß because there is no word in the german language that uses it as the first letter. the german language didnt think of allcaps. please correct me if I am wrong. If written in uppercase it should be converted to SZ or the new uppercase ß…. which my iphone doesn’t have… and converting anything to uppercase SS isn’t something germany wants …

> there shouldn’t be an uppercase version of ß because there is no word in the german language that uses it as the first letter. the german language didnt think of allcaps.

Allcaps (and smallcaps) has always existed in signage everywhere. Before the computing age, letters where just arbitrary metal stamps -- and just whatever you could draw before that. Historically, language was not as standardized as it is today.

I don’t think that Germany wants a capital ß or the German language requires one rather technology needs one to dot the eyes and cross the tees.

Not generally no, but some applications used it that way because of ambiguity of upppercasing ß to SS - which is why ẞ was added.

On the other hand, the German language has existed for several hundred years without having a capital ß but now it needs one?

True capitalisation has always existed but even that didn’t seem to have required a capital ß - why now?