I am a 47 year old musician
How does being talented in x equate being talented in y?
It doesnt necessarily do.
In this case being a musician doesnt mean you know anything about video game racing.
It only means you can play
guitar, piano, drums know how to sing,
Also, you age doesnt matter, there are people of younger and older who are both worse and better than you - in both being a musician as well as video game racing.
With these 2 facts, your wall of text has been reduced to:
"I dont want to accept the fact that the game Gran Turismo has an inherently higher difficulty level than I can handle with the effort I am willing to invest."
And that is as fine as it can be, because I cant do some other things I would like to do for various reasons, like playing sports because my physical fitness has had a rapid decline after hitting the age of 20.
But even before that I would never be able to compete at certian sports because I would have lacked the raw talent from the beginning.
But other than that, I really like doing hardmodes in video games of all sorts of things, and most of the time I dont consider them difficult while sometimes I do and accept defeat.
With a bit of research it would be possible to verify this claim, but I dont see you wanting to do this - and it doesnt matter at all.