English, like most if not all languages, has what are called Negative Polarity Items (NPIs). NPIs are words or phrases that have to be scoped under some sort of negation, irrealis, or otherwise nonaffirmative clause. One example in English is "ever". We can say I haven't ever been to Atlantic City, because "ever" is scoped under negation. We can say I wonder if John has ever looked at syllable-initial geminates, because if-clauses are irrealis or nonaffirmative. We can ask Have you ever ridden an elephant?, because questions are nonaffirmative (they don't contain any at-issue assertions). But we can't say *I have ever been to Jane's house, because this is a declarative, positive sentence that makes an at-issue assertion.
For most(?) people, "anymore" is an NPI. Thus for most native English speakers, I don't smoke anymore is fine, whereas *Young people are so rude anymore is bad. However, there is a small subset of American English speakers (and possible speakers of other dialects) for whom "anymore" can be used in positive contexts, as in the second preceding example. My grandmother was one of these, which is probably the only reason I know this. For her, it was fine to say "The buttons on phones are so small anymore". I can't think of a good way to easily find good examples of these constructions on, e.g., google or COCA. Suggestions would be welcome.