I mean not from the pop-up menu, but as actual individual keys just like A, B, C, etc... Try typing texts all day and having to access the pop up menu three times per word.
Yeah like I'm going to do that every time I type an accented letter. Imagine if to type any vowel in English, you'd have to press and hold then select a letter from a pop up menu, it would be so inconvenient you would not do it. It slows you down about 300%. It's great for typing the odd foreign word, but not for typing in that language in general. So then you end up typing without the accents, and you can still figure out what the person what trying to type, however, auto-correct becomes useless because for iOS's auto-correct, "A" and "Á" are just as different as "A" and "Z", so you either have to disable auto-correct (which makes it difficult to type accurately) or you have to tap-hold-select-let-go every other letter, or you have to put up with auto correct correcting words like "dog" into things like "Mississippi" for no reason (and I'm not exaggerating that much).