I seriously understand, as I am much the same way, but...
there are sometimes gains to be made just thru practice and sheer determination.
There are higher or more outwardly forthright, over-the-top vocals that I could not pull off at first, but managed eventually after many, many retakes.
There are many cases of me standing on my toes and reaching for the cieling in order to nail the highest parts.
I am by no means a vocalist, but I have many cases in which I've hit the mark or increased my range, just by working it.
A lot of it is in the breathing, and vocal chords have limits but can be trained.
(As an asthmatic and former smoker, I typically don't have the wind to pull off really great vocals).
There's certainly reason to know there is only one Steve Perry, Paul McCartney, David Bowie, etc.


