Citation needed? I don't believe this is true. And techniques like payment channels allow you to stretch a significant amount of mileage out of a single transaction. The Sia network for example has payment channels that have over a million payments made per on-chain transaction.
That's also the role of prices - they are signals for people to take action, provided the actors are free. Prices as an information signal simply fail to work when entities like the government use coercive force to interfere. Prices also fail if the markets are based on coercion or violence towards others.
Crypto or fiat, there will never be a totally unregulated market that works.
In a way, it's like Star Trek TOS epispode "A Taste of Armageddon" - you can't replace war with a simulation (and then voluntary euthanasia). You won't resolve international conflicts through a friendly match of Q3 Arena. It's an unstable situation, because anyone who disagrees with the result can just pick up a club, or a gun, and force their own result - at which point you're back to square one. And so it is with unregulated markets: someone feels cheated, picks up a gun, and you're back to some form of governance.
"Massive court system with a massive law enforcement arm" doesn't exist just for the large financial institution. It's the baseline, arguably the core piece of social infrastructure. Beyond finances, it serves to protect just about any kind of dealing that involves more than two people. It allows society to coordinate. So if you want to count that in, be sure to limit the scope to just the impact on securing financial deals - otherwise, you'll have to include on the crypto side of the ledger the costs these institutions incur so that crypto developers can spend their days developing financial systems, instead of hunting animals for food with rocks while hiding from the local warlord.