There aren't any ground stations in the open ocean, so it all has to be routed between satellites to hop to one that has a connection to one. So it is a congestion issue.
It might well be a "dumb pipe" implementation (i.e. no regeneration and smart inter-satellite routing on the satellites), although Starlink does significantly mention an "onboard eNodeB modem", which sounds like it should be possible to forward that over the laser links.
Have they incorporated the laser links into prod on their sats yet? I thought that they were launching sats with them yet hadn’t successfully routed traffic yet through them in prod which is why they have a limitation to near the coast.
Yes, the open sea connections wouldn't work at all without them. But I think they're still a minority of the fleet and it'll take a while to eventually upgrade to full coverage.
There aren't any ground stations in the open ocean, so it all has to be routed between satellites to hop to one that has a connection to one. So it is a congestion issue.