expendable
adjective uk/ɪkˈspen.də.bəl/ us/ɪkˈspen.də.bəl/
可有可无的；无关紧要的；不必要的
If someone or something is expendable, people can do something or deal with a situation without them.
No one likes to think that they're expendable. 谁也不愿意认为自己无足轻重。