This kind of thinking is wasteful.
Every d20 has a finite lifespan. It was created, and it will, at some time in the future be destroyed, as all things are. That means it has a finite number of rolls in its lifetime, with an equal distribution of all possible outcomes. When you “practice roll” and get a nat 20, you have wasted one of the limited number of nat 20s that die has in it.
Think of the 20s. Don’t practice roll.
This is like a common house fly worrying about the lifespan of Cthulhu.
You haven’t seen how some of the folks I play with roll.
i assume revenge for stepping on a d4 once?