You're right. There are no markets in which a few dominant players capture significant profits because there are only a few dominant players who exploit barriers to entry or network effects to stay on top...

Except pharma, telecom, energy, airlines and one or two others...

The barriers to entry with ride sharing are absurdly lower than anything else on that list. The network effect is pretty weak, because it doesn't cost consumers/drive more time or energy to keep multiple apps on their phone.

Other than pharma, you just mentioned 3 industries that have very low margins. They aren't making a ton of money on their monopolies.

Indeed I think he proved my point.

I am not sure who would like taxi industry to pharma?