Understanding correlation won’t help you with decision making and initiatives measurement in a business setting. A solid grasp of causality is what you need.
Whether you are a Data Scientist dealing with Decision Science, Marketing, Customer Science, or effective A/B testing, Causal Reasoning is a top skill you should master in your career. Disentangling cause-effect relationships is typically overlooked in business and is a largely poorly understood practice. Many key decisions are taken on anectodical evidence, many wrong conclusions are driven by spurious correlations. This can go from spamming customers for no reason to disastrous waste of money due to incorrect initiatives.
Truth is that mastering causality when dealing with human behaviour or socio-economic systems, by definition chaotic and multivariate systems, is damn hard. Yet being able to frame problems in a causal fashion greatly helps give some order to the chaos.