Why did Antonio Brown leave the Steelers? Pittsburgh exit marked start of problems for former Buccaneers star

Brown was named a Pro Bowler seven times as a member of the Steelers and climbed all the way up to second place on the franchise's all-time receiving yards list. So why did he leave Pittsburgh?

source https://www.sportingnews.com/us/nfl/news/antonio-brown-steelers-buccaneers-leave-pittsburgh/1lqi6wc8ebc0f1mub4yp4aaahi