No new antibiotics have been developed for over 30 years

Bugs are evolving to become resistant to the existing drugs

Each year in the United States, at least 2 million people acquire serious infections with bacteria that are resistant to one or more of the antibiotics designed to treat them. At least 23,000 people die each year as a direct result of these antibiotic-resistant infections.
U.S. Department of Health and Human Services

Unless we take global action, antimicrobial resistance will become an even greater threat to mankind than cancer currently is.
April 2016, George Osborne, Chancellor of the Exchequer

If we fail to act, we are looking at an almost unthinkable scenario where antibiotics no longer work and we are cast back into the dark ages of medicine where treatable infections and injuries will kill once again.
July 2014, David Cameron, Prime Minister UK

Antimicrobal resistance could cut global GDP by 3.5%, a cumulative cost of $100bn (£70bn).