Tien being the "master of copy" is said no where in the manga. All Tien said was that he can easily copy techniques like the Kamehameha. If you're going to make a point, at least don't make stuff up. Tien also fought Yamcha, but didn't bother to copy the Wolf Fang Fist. He also didn't copy Roshi's hypnotism, despite him seeing the fight with Man Wolf. Instead, he copied two techniques that we saw Goku copied three years ago. And Goku couldn't copy the Four Witches since it's literally a racial move. Flying is more ki control than copying, but I never claimed Goku can copy everything like you're pushing with Tien.
You're the one making up canon by claiming Tien is a copy master when no such statements exist any where and it was a boost from Tien saying that he can easily copied no level stuff like the Kamehameha. And, pet peeve, it's canon not 'cannon'.
"Tien can copy anything", is quite frankly your hesdcanon disproven several times in the manga, which you try to hand wave as 'Toriyama forgot'.
Gohan called it easy, compared to going Super Saiyan, not that it was the easiest thing in the world to learn. Gohan also said anyone can use ki, yet look at how many ki users existed in early Dragon Ball. Goten and Videl had to be taught ti fly, they just didn't pick it up watching others do it.