These are not the only marks used in German, Spanish and French. There are many others, like accent marks, and it is safe to say that there are very few languages that do not use one or more diacritics to help the speaker produce the correct sound.
But what about English? We have the acute and grave accents, the circumflex, the diaeresis, the macron, and the breve. But they are mostly used by poets, or when we are writing foreign words. Most people never use them and our QWERTY keyboards don’t have them.
Punctuation marks like the comma and the exclamation mark are not diacritics because they do not affect the sound of a letter. But I can’t resist mentioning that most interesting little dot over the ‘i’ and the ‘j’. That tiny thing is called a tittle. In the phrase “No jot or tittle” the word jot comes from iota, another word that means ‘very small’.
If we decorated our spelling with diacritics we would end up with a language looking very much like Vietnamese. That language is tonal and needs about a dozen diacritics—sometimes two on one letter—to get the correct tonal sound. This can be a major problem when we adapt a tonal oriental language to our western alphabet.
Instead of adding diacretics to words, the English language uses a wide variety of spellings, including over thirty diphthongs and digraphs and a number of markers. They are often awkward and even frustrating, but most readers will agree that it is better to put up with our weird spelling than to struggle with a dozen or more diacritics.