I think we're still looking at an early prototype of Starlink, and there's potential to develop it in many ways as our space infrastructure develops. After all, space tech is only now advancing after decades of stagnation, driven by the reusable rocket. It's hard to think the company that invented the reusable rocket is also all in on disposable satellites, so we have to consider why that is.

The big problem is that things in LEO experience atmospheric drag and need to be boosted occasionally. Starlink sats have ion thrusters to do this and effectively reach EOL when their fuel is depleted.

On-orbit refueling is another core SpaceX goal, and there are also other companies launching experimental sats and tech demos to refuel satellites or otherwise boost them. So someday we will probably have a fleet of shepherd sats fueling and maintaining Starlink.

So why not just bigger fuel tanks then? I think they want these to come back down. Starlink is a massive beta test that turned into a full rollout way faster than expected and a large fraction of the satellites are already obsolete. However as people have already come to depend on the service, they have to keep it working as they progressively improve the satellites. And the easiest way to do this is just to let the old ones burn up and free space in the shells for new ones.

They can't even launch the real v2 satellite without Starship as the current sat is known as the "v2 mini" and is shrunk to fit in the F9 fairing. I would guess that these Starship launched versions will have bigger fuel tanks and a longer life.