I’m sorry you are having bad experiences.
However, in ANY field, employers may react negatively to any applicant who appears to have not stayed in jobs for longer periods of time. All employers want to see a pattern where one person will stay with an employer for a number of years.
Yes, RNs are having to take on larger roles in managing less experienced staff. That was the pattern for years in the armed services.
Also, the market for RNs apparently varies greatly between different areas of the country. That has always been the case - I can remember reading my sister’s nursing magazines 25 years ago when they were filled with ads from hospitals in rapidly growing parts of the US.
One factor is how many nursing school grads are produced in a state. Another factor is whether a state has agreed to participate in the expansion of federal Medicaid, which can generate thousands of jobs because there is less uncompensated care. Also, when increased numbers of residents gain medical insurance, they come in to have many health problems treated that they had delayed in having addressed because of financial reasons. As a result, there is more business for local health care providers and more need for RNs.