Why does Prosecco typically lack the yeasty, bread-like notes found in Champagne?

Because Prosecco's fermentation avoids extended contact with lees in the bottle typical of Traditional Method wines.

The absence of complex, savory, yeasty, or brioche-like notes in Prosecco, which are hallmarks of Champagne, is a direct consequence of its standard production technique, the Charmat or tank method. In Champagne, the secondary fermentation occurs inside the bottle, and the wine remains in contact with the spent yeast cells, known as lees, for a minimum of 15 months. This extended contact is what develops those secondary, complex flavors. Since Prosecco fermentation happens in large, pressurized tanks, the wine is racked off the lees much sooner before bottling, resulting in a profile that emphasizes primary fruit characteristics rather than these autolytic (yeast-derived) savory notes.