"Actually, 40 Years Of Data Show The MBA Effectively Does Nothing -- It Has No Impact" - Business Insider
https://www.economist.com/whichmba/nothing-special-mbas-are-...
MBAs are no longer prized by employers - The Economist
There's a lot more links like that on Google, I'll leave it to the reader to find them. That said, I found this one interesting:
Https://www.google.com/url?sa=t&source=web&rct=j&url=https://amp.theguardian.com/education/2018/mar/19/why-the-mb...
It's an article in the Guardian that, to give the tldr version, suggests that MBAs retain usefulness for getting jobs, but with no evidence of impact on capability.