24-50mm is only a 2.08x zoom range, but I see it as four important focal lengths in one lens: 24, 28, 35 and 50. If you look at that way, a 35-100mm is also essentially four: 35, 50, 85 and 100. And a 28-75 is also four: 28, 35, 50, 75.
By comparison, a 24-70mm is a 2.9x zoom range, is almost twice as big & heavy as 24-50mm, but only adds 70mm. A 24-70mm is more useful, but at considerable extra size & weight.