That said, it isn't really regulatory hurdles that create big barriers to entry. There is some truth to that in a handful of ultra-regulated industries like insurance where they require insurance companies to have huge amounts of money to back up their policies. That said, you do kind of need to have a lot of money if you're going to honestly offer policies that could potentially cost huge amounts of money, for example, in a natural disaster.
But generally speaking, regulators are generally the only thing keeping the competition alive at all. In a totally de-regulated market, you pretty much always end up at a monopoly. Monopolies are so much more profitable than competitive markets that companies always find a way to make one work. For example, if you're selling widgets, maybe you pay the trucking companies not to haul your competitor's widgets. Maybe every time a small company tries to set up shop in the widget market, you just drop your prices so low that they can't compete, then you jack them back up again when the competitor goes out of business. Or, maybe you just merge with all the other big players. Antitrust regulators are constantly battling those sorts of things. IMO, the solution is much more aggressive antitrust regulation, not less regulation of other things.