There are several non-constructed languages, including English, in which almost all words end in consonants, but what about a language in which almost all words end in a certain type of consonant? In my case, I'm trying a synthetic language which relies on different types of fricatives at the end of words to show grammatical meaning. The language has several non-fricative consonants, but would it be realistic for those consonants not to form endings while the fricatives do?
Yes, of course, that's entirely possible!
See also word-final voicing in Basque, which is an example of a sound change that affects word-final consonants especially much. Conceivable, such could also lead to spirantization (plosive>fricative) word-finally. (And there are certainly more other ways such a trait could come to be)