The phrase "more infrequently" implies something is happening less often than before. There are many synonyms that could be used instead of "more infrequently," such as "less often," "scarcer," "sporadically," "occasionally," "less frequently," or "rarely." For example, "The dog barked less frequently after its owner scolded it." Or "The company's profits have been declining sporadically over the past year." These alternatives convey essentially the same meaning as "more infrequently," yet each might provide a slightly different connotation or emotional emphasis - depending on the situation and desired effect.