Decision fatigue
Etymology
From "decision" (Latin "decidere," to cut off) and "fatigue" (Latin "fatigare," to weary). The term emerged from social psychologist Roy Baumeister’s research on "ego depletion" in the 1990s and 2000s.
noun phrase · /dih-SIZH-un fuh-TEEG/
The deterioration of decision quality after a long session of making choices.
What it names
Explains why choosing gets harder as the day wears on — willpower and judgment seem to run down like a battery.
Example
By evening, decision fatigue had set in, and she defaulted to takeout rather than face one more choice.
Related idea
Choice overload is about too many options at one moment; decision fatigue is about too many decisions over time wearing the chooser down.