What else can international physician work in USA without USMLE?

You might look at Emergency Assistance Companies who hire medical professionals to support their operations.

As an international graduate, I completed the boards to become a physician. Although there are other options without USMLE, I do suggest going through ECFMG certification to become a doctor which is a very lucrative pathway. If you either prefer other opportunities or couldn't enter residency, the available options are research, medical scribe, medical assistant, physician assistant, college professor etc. Talking about research, you might have to begin with volunteering in a lab or clinical trials first to gain experience which can open doors to a paid position. However, you have to work hard to find one unless you have good contacts. But very doable for a person who consistently tries, reaching out and showing genuine interest. Medical scribe companies or local hospitals have scribe positions- part time/ full time with/ without a training. To become a physician/ medical assistant you have to follow a college program and get certified in the state which can take few years.

People with foreign medical degrees aren't usually allowed to just jump into medical practice. If you want to be a nurse, nurse-practitioner, physician assistant, etc., you must graduate from their programs and get their degrees. I am a physician assistant and have taught students for many years. Many of those students have been foreign medical graduates. They are treated the same as any of the other students and expected to pass the same curriculum. There is no short cut.