If you think same-sex marriage is immoral, you certainly think the US is far less moral than it was before 2015. ... We can settle eternal questions of right and wrong later. For now, we only care about the parts of morality where pretty much everyone would agree ... things that we can all agree are bad.
Okay, goodbye, pedants! Onward to the science.
This is what passes for serious religious discourse at Real Clear Religion.
In 2001 just 40% of Americans thought same-sex relations were acceptable. In 2023 it's 64%, but down 7-points from last year, according to Gallup.
The overall increase is indeed a measure of moral decline, but The Science™isn't particularly interested in that, nor in why millions of people suddenly changed their minds about it again in 2023.