I'd say, if your company offers (a track) to an MBA, take it. It's free, often partly in company time (get paid to study, partially), puts you on the fast-track to succession with HRM, sends a signal to any future employers that your previous employer marked you as a high-potential, worthy of investing in.

I also recommend doing a Master's in a business field if you're 22 or so in a country where it makes sense. e.g. in continental europe it's pretty common to do a 3y bachelor from 18 to 21, and a 1y master's. The 1y master is a relatively small investment, and e.g. in the Netherlands where most unis are ranked top 100 worldwide, the cost of a 1y master's is about $2k. In 19/20 cases (making up a number), the added value of the learning/status/grit of this 1 year experience outweights the $2k+Opportunity-cost of spending this 1 year instead of working, it's an easy decision.

For anyone else? e.g. self-funding a $100k program, spending 1-3 years and having to forgo work (without company support) when you're in your 30s, probably not a great idea, on average. At that point the value is mostly learning, at a huge cost. And in my experience, self-study vs college-study in the field of business is terrific. The resources for self-study are gigantic, lots of great books, youtube videos per topic and entire courses from Harvard or MIT are online, including online testing environments where you can do exams, and lots of cases that you can buy and work through, all at a 1% cost of an expensive MBA. It's not exactly the same, particularly for a few business schools which are actually great and add value, but it's pretty damn close in most cases.