Don't judge easiness of learning language based on English - its one of the easiest out there to learn (I speak 5 languages and english is absolutely trivial compared to others), especially for folks with similar base (ie roman/germanic ones). Slavic languages are much harder to learn and basically useless outside given country (with few exceptions but usable mostly for C2 or natives level).
Also, compared to many other languages even very basic level of english gets you somewhere, in some languages like French natives basically refuse to speak to you or simply don't understand you unless you have cca B2 level (this is personal experience of me and folks around me where I live)
I've never seen this happen, but I do notice a lot of tourists asking for services or starting conversations without saying 'hello' or 'bonjour,' which is considered disrespectful in France
If you use cursor, cursorrules can be a good way of doing this.
I will keep using LLMs for 1 week greenfield hobby projects that I don't plan to revisit. But no matter how good LLMs get, I will never use them in my dailyjob, otherwise, I risk losing touch with the codebase.