The vast majority of germs won't hurt you and are mostly beneficial. A very small number are pathogenic. Generally, outside of environments where people might have compromised immunity, we're better off being exposed to them.
This I explained to the delightful Vivian in the Apple Store as I disrobed my iPhone of its case to reveal a rather grubby phone.
Antibiotic resistance is simply evolution in action, so creationists are exempt.
The reasons for antibiotic resistance are primarily poor practice by medical staff, a lack of joined-up approaches, non-adherence by patients, poor healthcare systems in many countries, along with industrial use in animal feed. Vast quantities of front-line antibiotics are fed to pigs creating a huge reservoir of resistance genes.
There is no shortage of potential antibiotic chemicals (because of that same evolution) – perhaps not infinite though – and, of course, the majority won't make safe or useful medications, after all you could drink bleach, it's a very effective antibiotic. The reasons why so few have come to market are various – drug development is, to a degree broken, any business will chase the best revenue opportunities and perhaps that's not the best approach to life-saving pharmaceuticals. And to be fair to drug companies, the cost of bringing a drug to market is HUGE. Any drug is a massively high-risk investment. Also, everything is skewed by the vast sums of money in the US healthcare market (which we can laugh at and shake our heads sadly, but ultimately affects us all). Very few new drugs have come to market in recent decades – large numbers of me-too drugs offering debatably incremental improvements and very expensive risk-reward targeted monoclonals.
And while it's fine to suggest public development, the costs are still HUGE (unless we remove the regulatory burden and liabilities, which we'd also then have to do for businesses) and someone has to pay them. People only tend to worry about the costs of healthcare and treatment when they're sick or know someone who is sick.
