Why do abusive people lie, spread rumors, and make up malicious gossip? To shame and effectively isolate targets, that’s why.
Narcissistic people are the ultimate social and emotional predators. Truly functional — rather than dysfunctional — they are vicious predators whose only intention is to win at all cost. Competing in their own mind financially, physically, socially, and emotionally with every single person they encounter, they project their own negative qualities and errantly presume their targets have similar core values by nature.
It’s totally normal for a person with a Cluster B personality disorder to pathologically lie, gaslight, and smear campaign. It might be absolutely dysfunctional and caustic to themselves and others, but the pattern is stereotypical.
Don’t expect to be able to avoid having to deal with their self-serving antics and shenanigans. Every narcissistic person you know who actively badmouths another person or group without that person or stereotype represented is keeping a major secret from you.