Why the Same Flight Takes Longer Now Than 30 Years Ago

[ergophobe]

Short answer: Goodhart's Law

http://www.bbc.com/capital/story/20190405-the-secret-about-delays-airlines-dont-want-you-to-know

[littleman]

Interesting article.  One thing they didn't mention is that the high bypass turbofan engines that modern planes are using get better fuel economy, but also propel the planes a bit slower than the low bypass engines of older commercial planes to gain efficiency.