Starlink gets a lot of attention because it's new, and because it's run by a polarizing guy who sucks.
Meanwhile, the airplane and streetlight situation has been destroying night sky photography for decades, to the point where photographers consult charts and have communities tracking the best times of years to minimize the hours of driving you have to do.
But let's "both are real issues" it, sure.
It still won't be as big of an issue for night sky photography, for reasons mentioned in the parent comment.
However, there are many other severe issues, of course. But for hobbyist and professional photography? Mitigable.
I can see a problem with 100x the current deployment, but the "other severe issues" kick in long before that, anyways.