The definitions of love and relationships have really changed in the last twenty years, and people are creating lifestyles that better suit their relationship orientation. Many people are exploring new ways of living and being with each other, creating families that don't necessarily look like the traditional families of the 1950's (unless that's your kink.)
As we expand our ideas of what relationship and family means, it's important to emphasize that non-monogamous relationships can be just as happy and healthy (or unhappy and unhealthy) as monogamous relationships.
Monogamous vs. non-monogamous relationships or hierarchical polyamory vs. relationship anarchy: one form is not better or more superior to another. People choose which arrangement is best for them: monogamous folks might enjoy that sense of being someone's 'one and only' while non-monogamous folks might enjoy the freedom to explore relationships with multiple partners. There are as many different relationship configurations possible as the number of people living in them.
What's important is how you show up in these relationships, making sure that the needs of all involved are respected and considered, including your own. Relationships can easily become complicated and stressful, but having the tools to navigate them successfully can help them reach their higher potential.