If betrayal is defined as selfishly pursuing one’s own interests over the interests of others, most everyone betrays each other, at least in small ways, every day. Only large betrayals usually draw personal or social complaints or punishments (e.g., infidelity, theft, treason, etc.). But, as subjective beings with needs and desires, everyone is faced with a kind of inherent, moment-to-moment conflict-of-interest with everyone else, and sometimes within ourselves, namely: do I do what someone else (or a part of me) wants/needs, or what I (or another part of me) want/need?
For example… do I spend more time/energy on a certain person, or not? Do I follow my heart about relationships, career, etc., or do I do what my family or society want? Do I eat what my tongue, nose, or mind most enjoys, or what my body finds most nutritious? Do I help that needy person who looks or behaves differently than I prefer, or do I ignore, reject, or punish them somehow? Which is more important: my life/health, or the life/health of the plants and animals I eat — or, my family or country, or someone else’s family or country? Should I win, even if someone else must lose?
Selfless love is everywhere, but so is selfish betrayal, often in a complex mixture.
From a Buddhist perspective, the current human condition is inherently unfortunate, unstable, conflicted, etc. The point is to feel frustrated by it, to see the danger and pointlessness of it, and to seek a better state of being.