disaffected
No longer loyal to a group because you feel disappointed.
Disaffected means feeling disappointed with and no longer loyal to a group, cause, or institution you once supported. When people become disaffected, they lose faith in something they used to believe in or feel connected to.
A student might become disaffected with their debate team after watching the captain play favorites and ignore good ideas from newer members. Workers grow disaffected when a company repeatedly breaks its promises about fair treatment. Citizens become disaffected with their government when leaders seem to ignore what ordinary people need.
The word captures a turning away, a withdrawal of the enthusiasm and loyalty someone once felt. A disaffected member of any group has stopped believing the group deserves their support or energy after recognizing serious problems.
You'll often see this word describing groups of people: disaffected voters who stop participating in elections, or disaffected employees who do the minimum required and nothing more. The feeling combines disappointment, alienation, and a sense of betrayal. When someone becomes disaffected, they've emotionally checked out, even if they haven't physically left, because they no longer believe in the group the way they once did.