A bit academic but for those that have studied any finance course have probably come across the above Porter's 5 Forces which is a framework to assist in determining a company's competitive advantage and consequently a quality investment.

That is why I was interested to read the below articles challenging the idea or that link (same author):

1) The Gospel According to Michael Porter (institutionalinvestor.com)

2) Market Share & Profitability (mailchi.mp)

I did read on Twitter a few months ago a competitive advantage/moat, or whatever you want to call it, does not ensure strong returns on capital, it just defends the current returns on capital. Which i think is quite a profound insight which isn't taught by any finance courses.

Given the ACCC and the anitrust in the US seems dogmatically focused on market share (Coles and Woolies right now in Aus) as determining whether a company is too profitable it's probably focusing on the wrong thing.