In what browser does eager image loading interfere with "interactivity"? Let's face it, they know most readers probably don't read/scroll to the end so it saves

In what browser does eager image loading interfere with "interactivity"? Let's face it, they know most readers probably don't read/scroll to the end so it saves transfer costs on a decent scale --- which is fair enough. "Half a megabyte of packed JS" still sounds way overkill for delayed image loading.. =)