[itsyaboi]

Why would you need to shoot down all or even most of the satellites? Pop a couple, let the resulting debris fields do the rest.

[NickNameNick]

Kessler syndrome isn't magic. Space is big. Starlink satalites are small. And they're low enough thst atmospheric drag will deorbit must of the small debris very quickly.

[itsyaboi]

I disagree.

Considering that StarLink satellites have a orbital period of ~95 minutes, I doubt that debris fields de-orbiting "very quickly" as you so precisely put it will be quick enough.

And even so, just shotgun your payload of tungsten flechettes into a orbit a bit higher than the satellites and let gravity do the rest.

I'm sure people smarter than me have considered these scenarios and done the economic math.