I've seen German keyboards with buttons for the umlauts and ß, Spanish keyboards with buttons for accented vowels and Ññ and the upside-down punctuation marks, and Scandinavian keyboards with buttons for things like Åå, Ðð, Þþ, and Øø. I am shocked that anybody whose language uses the Roman alphabet could possibly still end up with a keyboard which doesn't do whatever diacritics are needed for that language, at this late date. So how in the world is it even possible for France to have ended up without something so basic this much later? and even my American computer I got 21 years ago (Apple, not IBM-clone) already had a button which, when combined with, ,, ,, or, would add the nearest-looking real diacritic to the following letter I typed if it could take it, producing things like è, é, ê, ë, ẽ, and ç, even though that was in the USA where our main language doesn't use them and foreign countries are much farther away and outside the realm of our experience for most of us.

What about your language? German Ö and Ü? Czech Č? Italian word-final stress marks like in 'città' or 'Forlì'? In Romanian, diacritics don't always appear on capital letters either. I'm aware that in Spanish the accent marks do not modify the vowel, they're just there to show word stress, but why not use them on capital letters, too, if it's an orthographic convention? It appeared strange to me, because in Hungarian the accent mark is an integral part of the letter if it's omitted, it's just plain wrong, it's a spelling mistake.

I remember seeing accentless all-capital inscriptions on French buildings, too. I was not familiar with the French poet, so I thought his name would be pronounced /malarm/, not /malarme/, as it should be. I've seen book covers that say STEPHANE MALLARME and LUIS SEPULVEDA, but inside the books the accents were used: Stéphane Mallarmé and Luis Sepúlveda. I've noticed that accent marks on capital letters are sometimes omitted in French and Spanish, e.g.

Uppercase e with an accent mark