What historical evidence is there to support the claim that societies which embrace promiscuity, homosexuality and variations of LGBT+ expression will decline?

seen from United States
seen from Japan

seen from United States
seen from Brazil
seen from Taiwan
seen from United Kingdom
seen from United States

seen from Malaysia
seen from Syria

seen from Switzerland

seen from United States
seen from United States
seen from Canada
seen from United States

seen from Malaysia
seen from United States

seen from Switzerland
seen from China
seen from China
seen from United States
What historical evidence is there to support the claim that societies which embrace promiscuity, homosexuality and variations of LGBT+ expression will decline?