Well this 2005 post from Joel Spolsky claiming that most people interviewed for a programming position can't code got a lot of attention. https://www.joelonsoftware.com/2005/01/27/news-58/ So it's not that 99.5% of all people can't code, but "the worst 199 keep applying for every job and never getting them". If you don't have screener questions, chances are higher that you have developers who can't code.