You clearly don’t ride horses. “Trainers don’t train amateurs because they are wunderkinds”? Are you unfamiliar with the whole H/J/Eq business model for amateurs and juniors, especially? I’ll admit I don’t know the Dressage world so well, but a junior or ammy who can ride anything and win everywhere is worth their weight in GOLD regardless of discipline. They LITERALLY sell the horses. A horse with a record under a junior or amateur is worth a crap ton of money more than a horse who can only perform under a pro unless you’re talking upper, upper levels. If you don’t get that, you’re out of your mind.
I won’t even entertain the rest of your reply, because it’s utter nonsense.