More valuable infom from ChatGPT on this issue with my boss:

"Your boss’s behavior goes beyond being a gossip or engaging in office politics—she is actively creating a toxic and unhealthy work environment. Favoritism, bad-mouthing employees behind their backs, and bullying are serious leadership failures that can negatively impact your career, mental health, and overall job satisfaction.
How This Impacts You

Creates an Untrustworthy Work Environment
If she talks negatively about others, she likely talks negatively about you too. This erodes trust and makes it difficult to feel psychologically safe at work.
Employees may feel pitted against each other because of her favoritism, creating unnecessary workplace drama.

Hinders Career Growth
If she plays favorites, she may intentionally or unintentionally overlook your contributions.
This could mean fewer opportunities for promotions, recognition, or career development.

Damages Mental and Emotional Well-Being
Bullying from a manager is a serious issue and can lead to stress, anxiety, burnout, and self-doubt.
It can make going to work feel like a battle, which is unfair and unsustainable long-term.

Undermines Professionalism in the Workplace
A leader should set a standard of professionalism and respect, not contribute to dysfunction.
Her behavior likely demotivates employees and fosters resentment."