i don’t think it’s so much a matter of dressin like the goyim, but more an issue of dressing in a mechubad manner. I find that as a frum Jew, we have an obligation to dress in a manner befitting our status. the son or daughter of a king would not go around in rags, and thats not to call jeans rags, but it, as an israeli woud say, “rechovi”- street wear. its not a material which implies royalty, which is what every Jew is, and if we are royal, shouldn’t we make sure to be proud of it?