Earlier quoted context omitted.
Regulation is the worst solution to any of this. Let the free market figure it out and you'll find enough competition if there really is enough demand.
The "free market" will always, always end up with large fish eating up the small fish and extracting rents once the competition is eliminated and the startup costs too high for startups to enter the market.
I still think this has much more to do with market interventions enabling 'artificially' large economies of scale. Infrastructure, police, subsidies/grants, IP protections--all played and continue to play a massive role in shaping markets today.