Tom Brady, who many people consider the greatest quarterback in the history of American football, still has a throwing coach (Tom House [1]), and he's still debugging his throwing motion. After 20+ years of throwing in a professional league.
So, for sure, unlearning habits is difficult, but learning only proper form from the start is probably an exceedingly rare exception. I think for most people the process of learning will involve learning incorrect form first, and attempting to fix this later.
My pole dance teacher once pointed out how different my style of training was: most students would try a difficult new move a few times, then go back to practicing stuff they were ultra-confident at for a while, while I'd be more likely to keep on trying the new move with a bunch of different little variations, and to pay a lot of attention to her when she'd come over and point out things I was doing wrong, especially if it was a wrong thing that would make me more likely to hurt myself!
I kinda feel like I can do this because I remember how I improved my art by the long, painful process of analyzing what I was doing wrong. And also because I have much less ego invested in the new thing - I already have a thing I can do the heck out of, I don't give a shit if I look like a bumbling beginner when that is what I am.
"How to learn" is a skillset, which you have to learn along with everything else you learn in the first two or three decades of your life. Once you have it down it's a lot easier to learn stuff if you're willing to put the energy into doing it right.
One thing that your idea prompts is thins: as I have gotten better at learning things I have gotten better at just adopting as-close-to-perfect form as I can from the get go.
When I learned to play guitar at age 20, I had horrible form, and I did go through a period of unlearning habits (after a period of trying to have a "style" LOL).
When I learned to play pedal steel guitar in my late 30s, I was careful to start with good habits from the get-go. Same with snow skiing, banjo, and yoga. :D
I dunno how I'd approach this lesson when dealing with younger folks... it was a painful process, but learning that starting with good habits/ form makes things so much faster and easier is maybe just a thing people have to experience on their own.