Well I can understand the licensing requirements to drive a truck, a taxi, or to work as electricians or plumbers, no one wants untrained drivers or tradesmen on the road due to safety - but why is a license required for moving?!
For long distance, interstate moves it's federally regulated and requires a license.
Do a quick google search on 'moving scams' and this should give you a good idea why licenses and regulations are a good idea in this industry. It's ripe for scams and shady characters.
Unbelievable, some of the stories I could tell...
.... go on...
Step 1: encourage people to put the vast majority of their material possessions in someone else's vehicle, and pay for the privilege to do so.
Step 2: drive away.
Car movers are also notorious for this. The fun part there is that if you don't pay the new rate, they hit the road again and it can be another week before you get your car back-- assuming it hasn't been impounded.
If you see a car carrier unloading a car or two in or near a residential area or in a corporate parking lot, it's quite likely this is part of a relocation package.
My son, then living in Washington, DC, got a job offer in California. He had little time to find an apartment, etc., and it did not seem practical to spend what time he had driving across the country. We stuffed the trunk with what it would take, drove out to Montgomery County, and handed off the car to the mover.
Buying specific cars tends to mean they're all over the country. Easier to fly there, check it out, and have it moved for you. Car collectors, for instance, though I assume the rich ones don't have these problems.
Sometimes it's cheaper to buy a car in state X and move it to you rather than buying it where you live. Also other countries, etc, though I assume you put that in the same mental-category as "over water" :)
However, some people are much to trusting and don't think to.
Since these licenses are limited in number, yet sold freely, it's clearly a gatekeeping scheme.
State licensing varies but generally, it's easy as well.
Licensing isn't unusual - for instance, the person who cuts your hair (assuming you're in the US) is almost certainly licensed by the state. If anything, it's a little unusual that the practice of software engineering has no licensing.
(The question of whether there's a fundamental human right to run a moving or haircutting or software-writing business is pretty separate; I'm just answering why it's rational for a society to ask its government to have licensing. If you believe there is such a right, then that overrules this analysis, sure.)
From what I understand there's been a fair bit of pushback on this one. Mostly related to it being a ridiculous and supposedly racist imposition.
It's certainly possible to run an illegal, unlicensed moving business, just like it's possible to run an illegal, unlicensed medical practice... But most customers will opt not to do business with one.
But requiring a license to work in moving is a US oddity. Germany, for example, seems to work pretty well without (and we Germans have a reputation for licensing everything to death).
Also, if a field is licensed, merely advertising / setting up shop in that field without a license is something the government can go after you for, even if you don't have any customers yet. So if I start putting up flyers for my shady "moving" company with the intent of stealing everything and never being heard from again, the police can find my place of business and hassle me, or set up a sting move, or something. (Again, in theory - if all you get is a $100 fine, maybe this isn't an effective deterrent.)
The shady movers have leverage, because you really need your stuff.
Had she stole people's possessions in some scam seven times over with there being no evidence or some other reason why the theft could not be proven then I am sure the book would have been thoroughly thrown at her with the maximum penalties possible for not having the paperwork for moving across state lines.