Modulation / key changes have been used in music for ages but the style I’m talking about is the distinctive last verse (or chorus) sudden key change up to power through to the end. Seems to have come about sometime in the 60s/70s and was everywhere in the 80s onwards.
Examples:
Heaven is a place on earth - Belinda Carlisle
I will always love you - Whitney Houston
But who popularised it? What was the first big song to do it and set the style for the genre?
Probably not the correct answer, but a lot of Jim Steinman composed/produced songs have that cheesy power ballad flair to it.