You say that a necktie is clothing of the gentiles and so should not be worn. Trousers are also clothing of the gentiles. Should they not be worn as well?

ב"ה Shalom, What was clearly meant by clothing of the gentiles is that at perhaps some time in the past, a necktie was something used only by gentiles and thereby this garment distinguished them from Jews. In such a case, if a Jew would wear a tie, it would associate them with the gentiles. Therefore, there is no question in regard to trousers, shirts, shoes and the like , because these are garments which everyone wears and do not distinguish people as gentiles. In addition, what I wrote was that some of the the Chassidim FEEL this way and this was not established as a binding prohibition among all Jews, but as a stringency among the few. Clearly today neckties are very common among all people in including Rabbis and people in Yeshivas, and it is not considered as clothing of gentiles. None the less, there is still a strong basis for those who want to stay away from certain lifestyles and this should not be taken lightly. The Gemara (Sanhedrin 74b) states that in the time of Shemad= forced conversion of Jews to idol worship, if a Jew is ordered in front of 10 people even just to change the way Jews tie their shoelaces, (Rashi explains that if there were to be a Jewish aspect to tying the shoelaces which emphasized more modesty as opposed to the gentile way of doing it) the Jew must sacrifice his life and not do it the way he was ordered. I wish to mention another example of people being stringent when it comes to something which may resemble the customs of gentiles even in regarding to the common custom of decorating the Bet Knesset with flower in honor of Shavuot . I mention this since Shavuot is not too far away. . The Chayye Adam (131) says that the Vilna Gaon abolished the custom of setting trees on Shavuot because it was the custom of the non-Jews to do so in their houses of worship on special days called in Polish Zielone Świątki, which is an ancient Slavic festival celebrated in early June closely linked with the cult of the dead and the spring agricultural rites. As known today, you will find most Shuls beautifully adorned with flora in honor of Shavuot, since this Slavic festival is hardly known in the western world. All the best