Grammarly doesn't only check grammar. It also has opinions about the style of your writing.
Moreover, remember that Grammarly is a tool for native speakers of English, though it can help learners in some contexts. Some native speakers overuse the passive voice, which gives their writing a dull and impersonal tone. Sentences in the passive voice can often be rewritten in the active voice.
So Grammarly is asking you if you would like to consider
Refinement of laws can curb organized crimes such as money laundering and embezzlement.
Both active and passive are equally correct. You might choose the passive voice because the paragraph is about "organised crime" and not about "refinement of laws". Grammarly is clever, but it isn't clever enough to understand what a paragraph is about. So it gives you a warning, and lets the intelligent human consider the alternatives.