Dreams about being fired can often reflect feelings of insecurity or anxiety about your job or work environment. In your dream, the fact that you and your junior coworkers were fired may symbolize a fear of being undervalued or overlooked, especially since you mention that you are all younger and less experienced.

The choices made by your coworkers in the dream could represent different paths or outcomes associated with your own career fears. The coworker who went to a "very bad company" may symbolize a fear of making poor career decisions or that you might end up in a less desirable situation. The one who went to a competitor but in a worse position could reflect concerns about competition and how you measure up in your field.

Staying with the final coworker at the same firm but being sent to the basement might indicate a sense of camaraderie but also a feeling of being sidelined or put in a less favorable position. This could suggest that you and this coworker share similar concerns or feelings about your roles within the company.

Overall, this dream may reflect your anxieties about job security, career progression, and how your current situation aligns with your ambitions. It might be helpful to reflect on your feelings about your job and consider discussing these concerns with someone you trust or a mentor in your workplace.