The site loses its ranking because it was copied content

I was a competitor copy 100% of the content. My article was published a long time ago, but when they copy and publish it immediately lost their rank. After I complained, google deleted their results, but they copied it to another article and I lost my rankings.

Can anyone explain me this, maybe google is so stupid

Hi! Maybe Your Article was Spun article or Article link sites are bad Ones

Don't see the only Article maybe Backlink sites also bad If you loss rank