How does a financial data analyst improve budgeting strategies?

How does a financial data analyst actually help improve budgeting strategies like i get they work with numbers but whats their real role in making budgets better do they just track expenses or is there more to it how exactly does a financial data analyst use all those spreadsheets and reports to spot saving opportunities or predict future costs and can they really help a business or even personal budgets work smarter not harder like what tools do they use and how much difference can a skilled financial data analyst actually make in cutting costs or planning better just trying to understand if its worth working with one or learning these skills myself