Smaller sensor sizes, generally, work better with high zooms (with the exception of astrophotography). Look at broadcast TV cameras as an extreme example; those

Smaller sensor sizes, generally, work better with high zooms (with the exception of astrophotography). Look at broadcast TV cameras as an extreme example; those use sensor sizes even smaller than M4/3. It simply becomes impractical to build a very long focal length lens for a large size sensor that isn't telescope-sized. And even when people are shooting with full-frame lenses (e.g. on Sony), they often use an APS-C camera body because it has more pixels in the very middle of the captured image, with the assumption being that you're going to be doing a lot of digital cropping anyway to get more effective zoom.