Apple and Epic expert witnesses are butting heads on whether iOS users are locked into the platform amid other choices on the market, such as game consoles or the web.Credit: Epic GamesMichael Cragg, chairman of economic consulting company Brattle Group, testified Thursday on behalf of the "Fortnite" maker in the ongoing Epic Games v. Apple trial. One of his main arguments was that other versions of "Fortnite" are not a substitute for iOS play.Read more