Why is tetracycline no longer used?

In recent years, we've observed a trend of tetracycline being phased out of medical use. Could you elaborate on the reasons behind this shift? I'm curious about the scientific evidence that has led to this decision. Has the emergence of more potent antibiotics contributed to this change? Are there specific side effects or resistance issues associated with tetracycline that have become too significant to ignore? Additionally, how has this shift impacted patients who may have previously relied on tetracycline for their treatment? I'd appreciate a detailed explanation of the current understanding surrounding the decline in tetracycline's usage.