Bacteriophages were used instead of antibiotics in the Soviet Union, and are still used today in Georgia.
Bacteriophage evolve of their own accord, so phage resistance is temporary. Often the bacteriophage strain you need already exists and you just have to find it. This is much less effort than developing a new antibiotic.
US Medicine is for profit, and the money is in reoccuring treatment, not cures. So a never ending battle of cat-and-mouse is the type of R&D phramas would love.
A potential future scenario:
Keep going to your doctor to get a Rx for the latest strain or pay a monthly fee to a Bacteriophage-As-A-Service SV tech company to get the latest delivered right to your door you use in conjunction with a smartphone app.
The latter of which would have operated illegally until sufficiently large enough to hire insider DC lobbyists to gut the FDA.
Please provide numbers of patients treated with phages, time to treat one and efficacy numbers.
They are still in development and there are some technical hurdles, but before too long cheap, fast, and accurate strain typing should be ubiquitous. The next issue is then creating the specific phages, but the first stage is pretty close at hand.
Good luck trying to even get the bacterial sample to do it for quite a few kinds of infections. Lungs and other organs would need a good biopsy or at least really well done aspiration, handling of samples is very messy.
It is a good method to use in hospital settings perhaps where you want to sample anyway.