It's not meaningless. There's two reasons. Improvements along a particular dimension aren't always a given. If they said "Introducing the Apple iPhone 8 Plus

It's not meaningless. There's two reasons. Improvements along a particular dimension aren't always a given. If they said "Introducing the Apple iPhone 8 Plus, the lightest iPhone ever" they'd be lying. You can't assume that a newer model of something is always going to be more powerful. Language isn't purely literal. Especially when there's a limited number of words to market to people. You can't write a 10 000 essay. So mentioning a detail isn't just to communicate the literal facts, it's to highlight details, point out significant details. So when someone says "it's the most X ever" they are saying that the improvements are significant enough to make them notable.