Earlier quoted context omitted.
I just looked it up. The first Falcon 9 flight was June 2010. The first Falcon 9 with astronauts was May 2020. 10 years to get human certified.
That was also with a rush order on it due to the Shuttle's retirement.
In those 10 years Falcon 9 flew 84 times [1].
So I would think Starship needs to fly roughly a similar number of times before it will be human rated. Even if they launch one a month from now on, it will take ~7 years. So I think we're a while away from NASA certifying Starship for human flight, though I wonder in SpaceX would just put their own people on it regardless.
[1] https://www.popularmechanics.com/space/rockets/g32758515/fal...