I always love the cultural decline argument. It suggests zero sense of historical knowledge. Acceptance of lgbt views is actually a sign of a highly sophisticated, and elite culture. In fuedal Japan, Daimyo would take in young boys to raise to be samurai. They would bond by having a sexual relationship. All daimyo did it. If you didn't you would be weird. Despite being a warrior culture, the samurai still had open ideas towards sexuality and sexual expression. This relationship was considered honorable and sacred. A very famous example is Nobunaga Oda and Ranmaru Mori. This analogue is deeply contrasted with the Spartans, who also were a warrior peoples and had trainers have sexual relations with their young vassals and assistants. Historically, in the art of war, homosexuality has been encouraged. Who better to fight with than one you love? This was thought to give armies power. These are usually birthed through the creation of highly sophisticated societies, often at their peak, culturally, in pre-industrial era times. It shows the fluidity of human sexuality.
The suggestion that lgbt rights is an example of cultural decline supposes zero self awareness or knowledge of self. It shows zero lack of knowledge of Greco-Roman, Japanese, and general history and makes one look to be a class S level distinguished mentally-challenged fellow.
Read a fucking book.