“why not?”
Finance and marketing majors typically have needed a grad degree (not necessarily a MBA) to have more career growth, senior corporate finance and marketing jobs are held by people with MBA, Masters in Accounting, say than just a BA or BS.
“I have not heard someone state that an MBA is the way to go in more than 10 years.”
Way to go may be too strong agree, but for the OP, an econ/MBA would do better than just an undergrad bus major. I’m generalizing so of course you can have exceptions.