She sits at home all day, watching TV and feeling useless.

她整天坐在家里，看电视、感到自己没用。

《柯林斯英汉双解大词典》

Due to the rain is too big, many white-collar but finished lunch had to hide in the restaurant, at the "rain" were left feeling useless.

由于雨势太大，不少午餐完毕的白领无奈只得躲在餐馆，望“雨”兴叹。

youdao

My son asked me to come help at his school track meet but I felt like a fifth wheel when I got there: they already had enough people to help so I just stood there feeling useless.

我的儿子要我在他学校开运动会的时候去帮忙。可是，我到了那里觉得自己似乎是多余的，因为他们已经有好多人在帮忙，我只好站在那里没事干。

youdao

While I have my deep reservations about the wanton nature with which we are throwing privacy to the curb, I do wonder (perhaps over-hopefully) whether the end of privacy might also herald the end of the often useless feeling of alienated embarrassment.

FORBES: Can Shame Survive In World Without Privacy?

With the growing popularity many other attractive features were included in Facebook, thus many started feeling that their Orkut account is useless and deleted their accounts.

FORBES: Facebook Surpasses Orkut, Owned by Google, In Numbers of Users in Brazil