Tax evasion happens, speeding happens, copyright theft happens, fraud happens. Until it becomes a big enough issue that they *have* to take note, they've always got better things to do, like making coffee, doing the paperwork, and hoping no-one notices.
I'm not condoning it, all I'm saying is it'll be taken care of only once it's an issue that they can throw a big enough book at

At the moment, all these guys running business UAV stuff without pfco & insurance are just low level noise and coppers and can have got bigger fish to chase... like parking fraud at East Midlands airport. That involved millions in anti competitive practices, but fines for those involved where all reduced to nil and wristies were slapped.
There'll always be lowballs that play to the bottom end of the market and are happy to use uninsured amateurs. Our best bet for keeping our jobs and income is to add the value the middle and higher end markets want, then uncle bob with his toy drone and poor quality video edits won't steal our business.
if you want to prosecute people, then go after those that use the uncle bobs, make it illegal to use anyone without insurance and permits, corporate liability. So basically you end up penalising those who commission and use the 'illegal' work. Easier to legislate for and easier for the boys in blue to get the evidence and prosecute. Do enough of them with some big fines, word gets on the street and most companies will start doing things properly. Jobs a good'un then. The problem is there's no penalty for anyone at the minute, those commissioning the work, and those performing the job.
Just my 2p worth