The LDS church downgraded same sex marriage from apostasy to a serious transgression this year.[1] The Episcopal church ordained an openly gay bishop in 2003.[2]
You said it's much better than others. Not that it's better than a lot of others. I think neither is true by American standards. Not even the Catholic church withheld baptism from the children of same sex parents.
[1] https://newsroom.churchofjesuschrist.org/article/first-presi...
[2] https://en.wikipedia.org/wiki/Gene_Robinson