In many fields of economic research, mathematical abstract formulas are useless, but there were more practical disciplines running through them before, and economics has become an interdisciplinary science. For example, the analysis of property rights, the analysis of regional economics and the study of international trade do not involve too profound mathematical principles. Of course, some behaviors of market stakeholders can be explained by mathematical principles, such as the law of large numbers.
If you are an undergraduate majoring in mathematics, you are more likely to transform into a discipline that emphasizes mathematical models, such as econometrics and financial mathematics, which will have a very broad application prospect in the future. Of course, as mentioned above, regional economics, industrial economics, international trade, international finance and other disciplines that emphasize practical experience and operation in specific business fields can be said to be very different from mathematics. In order to reform these majors, the department of mathematics itself has to relearn a large number of professional books, because these books are different from mathematics and more complicated.
All the above are for those who are interested in graduate school and research. Those who want to find a good job and study mathematics, especially those who graduate from pure mathematics, will lose their jobs. If you are willing to give up what you have learned and engage in other jobs that you don't want to close, that's fine. If you study economics, especially applied economics, you can basically get a job smoothly, and you are more or less engaged in your major, because economics itself is a grounded discipline, unlike mathematics or ivory tower science. Moreover, a considerable part of China's economy is driven by the tertiary industry, which needs economic talents to continue and develop. Both industry and commerce need economic talents to maintain.