Despite everything else, this is why George Washington is a big deal.

"When told by the American artist Benjamin West that Washington was going to resign, King George III of England said "If he does that, he will be the greatest man in the world."

Edit. Ok, so I found this regarding that quote.

Quote #1

"If he does that he will be the greatest man in the world!"

• George III to Benjamin West after learning George Washington was going to resign his commission as Commander of the Continental Congress and return to Mount Vernon.

George's Commission

You'll find this quote on the Fount of All Knowledge sometimes with a description of a meeting where King George asked his then-court painter, Benjamin West, what George Washington was planning to do now that peace had been agreed to. Benjamin replied (we read) that George was going to resign his commission. Then King George made his famous exclamation.

Certainly a great quote (and it also appears in some bonafide, albeit relatively recent, history books) it is indeed a "reconstruction". Its source is a memorandum book of Rufus King, the now-forgotten Founding Father who later served as minister to Britain. The book contained a letter written May 3, 1797 where Rufus wrote about a recent conversation with Benjamin West. The letter is (with modern spelling and punctuation added):

Mr. West called on me. We entered into politics after speaking of the Dinner at the Royal Academy and of the annual exhibition

Mr. West said things respecting America had changed very much, that people who could not formerly find words of unkindness enough now talked in a different language, that the King had lately spoken in the most explicit manner of the wisdom of the American government and of the abilities and great worth of the characters she produced and employed. He said the King had lately used very handsome expressions respecting Mr. Jay and and that he also spoke in a very pleasing manner of Mr. Gore.

But that in regard to General Washington, he told him since his resignation that in his opinion "that act closing and finishing what had gone before and viewed in connection with it, placed him in a light the most distinguished of any man living, and that he thought him the greatest character of the age."

So there was no record of any meeting with George III and Benjamin right after the Revolution. And the letter recording the conversation itself was written only in 1797 and is secondhand at best.

Still although King George may not have said exactly what is in the famous quote, certainly the sentiments were there.

Source: The Life and Correspondence of Rufus King , Charles King (Editor), Volume III, 1896

https://www.coopertoons.com/merryhistory/quotes/theydidntquitesaythat.html