The thing about this added coverage in remote areas is that they will only "never be served" by fiber because nobody wants to pay for that, not that it can't be done.
If you consider the monumental infrastructural and ecological impact of launching thousands of satellites instead of running lines, digging that 750km fiber trench starts looking way better.
I believe this is a case of externalizing costs and privatizing profits. In this example, for instance, we all have to breathe that rocket exhaust but it doesn't cost Starlink anything. Digging hundreds of long trenches likely creates dramatically less air pollution and other externalities than even a single satellite launch.
Regarding the "unservable" locations, such as the ocean, those problems can be solved individually, such as with drones, signaling relays, fixed wireless, and other technologies, some of which have not been devised yet because of market pressure from Starlink. Blanketing the planet with satellites so some boats can get online feels a lot like using explosive ordinance to kill a mosquito, and I'm sure we could do a lot better solving these edge cases than this global orbital network owned by private enterprise.