I don't think it's solely/mainly a question of volumes/numbers and being sufficiently well connected, though no doubt it is a factor. In my experience the 0.01% are privileged to play by the book, but have an advantage over the rest of us in having access to a whole library of books to choose from, and the money to hire experts in book-selection and lackeys to manage the whole affair on a day-to-day basis. That's the stuff a Tax-Haven-As-Service outfit would have to solve behind the scenes.
Most of these tricks involve entities-in-cahoots across multiple (usually at least three) jurisdictions, so I imagine it might take quite a LONG time before the various legal authorities in all relevant jurisdictions get sufficiently coordinated to have effective regulations in place. The evidence that this is the status-quo is that it exists, and has not, to date, been "solved" by any one government. Unfortunately it's just too expensive a solution to justify itself for us proles.
I have looked into what it might take to pull off some of these tax avoidence strategies for an average, upper middle income person. And the issue isn't just the knowledge, it's that you need a certain size before things actually start to meet the threshold of what the IRS and other foreign tax agencies consider legitimate.
One specific issue I remember running into was the strategy of offloading intellectual property to an offshore entity.
That entity needs to have staff and be at least doing something in regards to the business. I don't think you could get by just having an employee less or even shared entity holding the intellectual property. Because just an empty shell company is going to be seen purely as a tax avoidance play with no other purpose.
Most of these tricks involve entities-in-cahoots across multiple (usually at least three) jurisdictions, so I imagine it might take quite a LONG time before the various legal authorities in all relevant jurisdictions get sufficiently coordinated to have effective regulations in place. The evidence that this is the status-quo is that it exists, and has not, to date, been "solved" by any one government. Unfortunately it's just too expensive a solution to justify itself for us proles.
eta: Also Alderney (pop. 2000-ish)