“There’s one important thing to know about ‘Smiling Friends,’” the show’s co-creator Zach Hadel said during a recent Zoom interview with IndieWire. “It’s not smart.”

It was a reoccurring sentiment. Over the course of our conversation, Hadel and co-creator Michael Cusack repeatedly called their show “dumb,” “stupid,” “not smart,” and, in one colorful tangent, suggested that society would be better off if they were barred from producing television and sent to work in underground mines. But their humility masks a deep commitment to silliness that might be the secret to making “Smiling Friends” feel so damn refreshing.

The animated series, which follows an eclectic group of nonprofit employees who are tasked with making sad people smile (and are legally obligated to do anything a sad customer asks until they smile), was a massive hit in alternative comedy circles when it premiered on Adult Swim in 2022. The show...