It hasn't.
It has improved our communications, and knowledge of events outside our local area ... But it has actually decreased our standard of living, due to promoting a sedentary lifestyle.
how television have improved our standard of living?
I read that television has been a powerful teaching tool. By means of it, we learn about lands and peoples we may never visit. We “travel” to tropical jungles and polar ice caps, to mountain peaks and ocean depths. We peer into the intriguing worlds of both atoms and stars. We watch news as it happens on the other side of the globe. We gain insight into politics, history, current events, and culture. Television captures the lives of people in both tragedy and triumph. It entertains, instructs, and even inspires.