It would be great to have a more complete and versatile eraser. In Photoshop for instance you can use any brush for the eraser and it's an immensely useful feature.
I think a nice solution would be to have :
real-world presets : based on the existing pressure and softness settings but also adding basic shape control, so that we could imitate common eraser, kneaded eraser, soft vinyl erasers, etc
using any tool (or at least stickers) as erasers : maybe adding a "turn into eraser" option to the settings panel of various tools
The eraser can be a valuable drawing tool and really improve the creative process in many ways