[cycomanic]

That's simply not true. The throughput provided by starlink absolutely pales in comparison to an optical fibre link. AFAIK current plans might look at 100 Gbps transponders for the interlinks (I think it might even just be 10 Gbps). Even if they go to future 800 G or 1T transponders (which is questionable if it's possible, especially because most of the constellation needs this, so a whole exchange of satellites would be required), that's still much less than 70 Tbps that can be transmitted through a single fibre over submarine distances, and a submarine cable typically contains tens to hundreds of fibres.

So in short starlink will have no influence on available crosscontinental bandwidth.

Source: I research on optical fibre and space communication