The trouble is that, as a whole, antibiotics that work against resistant organisms are inherently more broad. Bacteria develop resistance by either mutating the target site of an antibiotic, decreasing/removing the expression of a target site, increasing removal of the drug from the bacterial cell, or preventing entrance to the cell.
These changes are relatively antibiotic agnostic (in the sense that they do not target one specific antibiotic, they target a general chemical structure which is shared among a class of antibiotics), and in most cases, if you develop a drug which is able to circumvent one of these problems, it will continue to work on the wild-type bacteria of that species (by definition making it broader). I am unaware of any antimicrobial which is effective against drug-resistant organism which has no efficacy against the wild-type of that organism.
I agree with the other poster that phage therapy likely represents a future avenue for antimicrobial resistance. Unfortunately antibiotics will (at least for the foreseeable future) be required as to effectively use phage therapy you must identify the organism and then select appropriate phages which will kill the bacteria, which takes time that a sick patient may not have without antibiotics. We also haven’t quite figured out how to keep our immune system from eradicating the bacteriophages, particularly for infections requiring longer treatment such as endocarditis.
There is a currently existing technology which allows for genetic identification of bacteria and fungi in positive blood cultures approximately 1 day faster than classical methods of culture and biochemical testing. There is active research into changing these tests slightly to be able to function on other body fluids (pus, pulmonary secretions, urine, etc) as well as to be able to function on fresh blood samples instead of waiting 1-2 days for the culture to become positive from bacterial growth, but these technologies are not ready for clinical use, and until they are, broad spectrum antibiotics will be a necessity.