Not gonna happen. The wold is full of antibiotics. Every organism on the planet is loaded with antibiotics. We keep finding new ones everywhere we look.
At the moment, we have so many antibiotics available that there is little research going into fully developing new ones. Most of the current research is very preliminary, sufficient to slap a patent on them.
Once it looks like there’s a market for new antibiotics, the research will start back up, but at the moment there isn’t really any market for new antibiotics. The old ones work 99% of the time. When they don’t, there’s already a slew of alternatives that work well enough when those don’t. Nobody’s going to go through the expense of licencing a novel antibiotic because there’s just not enough market to justify it.
The problem isn’t that we are going to run out of antibiotics. The problem is that we might run out of antibiotics that we can cheaply grow in a vat. We’re rapidly running through our list of fungal antibiotics, and those are the easiest to grow. The ones that we can extract from oak trees or walruses work just as well, but they are hard to mass produce. Kinda hard to grow a walrus in a vat.
However genetic modification will almost certainly allow us to vat-grow many of these antibiotics regardless of the natural source. But that’s a whole new source of expense in developing them, which is why it won’t happen until they can command more than a fraction of a percent of the market.