Internet on any ship is expensive as soon as you're out in maritime area - where data transfer is done via satellite services. So it is not necessarily because a captive market, where the cruise liners can fleece you. They pay crazy prices to the telecom/ISPs.
So if you're getting free internet out at seas, it is really at the cost of the ones actually paying the bills - or in this case, the cruise liner.
That's like saying your AWS egress fees are so expensive because AMZN pays so much for their bandwidth. Um, no, it's because it is a huge profit center precisely because the profit margin is so high
Could be, but getting a Gigsky e-sim is a lot cheaper than the internet on-board. And I was under the impression that in the end, that system is using the same internet uplink as the wifi (since I believe it's the ships themselves that send out the "Cellular at sea" network?)
In the "Cruise Only" section of https://www.gigsky.com/data-cruises it's $112 for 10 GB over 30 days. Per day that's certainly cheaper than $170 for 7 days but it's hard to say it's actually any cheaper per GB without knowing the other option's limit. Of course if 10 GB is enough for what you wanted to do in a week then it doesn't really matter but it might explain some of the pricing difference (ignoring bulk provider to provider pricing or other factors before we finally get to the "what do we think we can charge" pricing).
I'm assuming these large cruise corps can get a decent bulk/business discount though.
Pre starlink I looked at getting sat internet for 3 years around Africa. For even a few GB per month the cost was more per month than all other costs of the expedition combined.
I just got local sims, worked great
Pre-Starlink, no, not really. Some discount due to the bulk payment, yes, but the bandwidth is simply not there to allow for such discounts, especially in high-demand areas like Africa and the Pacific where satellites have a double-duty to serve land-based customers.