> No taxation without representation you cried.
That's over-simplified, a 1768 tweet (echoing a cause of the English Civil War in American context).
Our Declaration Of Independence is a charges-list against King George. Note that this is not aimed at americans, english, or George, but at other nations who might help the Colonies (for their own reasons) but were frightened by the idea of subjects revolting against a King (being most/all royals themselves). It paints George as a particularly bad King, overlooking the systemic grievances going back before his time.
Colonies are granted to make Kings rich. That's what Columbus promised; and while his didn't, others became pots of gold. Little gold on this coast so the UK kings took 'our' trees, food/beer, bunks, and took heavy taxes on essentials. Also ALL goods were supposed to go through London, even goods to adjacent colonies (see Australia). In return he was supposed to supply Governors and Judges but left posts vacant for long times.
In his defense, George had big troubles at home with money and people (not an unusual thing), and "had" to exploit his lesser subjects to keep his head above water. Losing the american colonies put an extra crimp in his purse for the next few decades. Aside from general revenue, Ship Masts became a real problem. This and other factors led the UK, in Napoleonic times, to impressing US merchant seamen, agitating "Red Indians", burning the Pink House, and other rude acts. We say War of 1812 but you see it in larger context. The north shore of then-Massachusetts was essentially UK-occupied for several years (leaving bitterness that ripened in 1820).
IHMO, the real cause of the 1776 revolt is limits on profits of Merchants. The Colonial Merchants became very good at both growing and converting stuff. But shipping everything through England paying taxes at each step... What if we bought sugar straight from the tropics, made rum, and sold direct to France and Spain? Packaged tobacco in Virginia and Connecticut, mast-logs from Maine, and sold globally direct? Carried anybody's cargoes there and back without London sticking a beak in? In innocence it sounds like fabulous wealth. So IMHO much of the actual push came from the large merchants and brokers. Would a more inclusionary policy from George allow him to tap a lesser percent of a much larger volume of trade, and benefited all? We can look to Canada. When Lizzie visits Hudson Bay Company she is still royally entitled to one dead beaver. (She asked the last one to be delivered live to a zoo.) However the parallel is tangent.