I've been on two Caribbean cruises that used Starlink for internet service, Celebrity Reflection in December and RCCL Symphony of the Seas a couple of weeks ago. Starlink is so much better than the poor internet service I've had on most other cruises -- I can watch videos, use a VPN client, or do anything else I normally do. I will definitely consider whether a ship has Starlink when planning future cruises.
Note that even Starlink can't guarantee that you'll have good WiFi access everywhere on the ship -- it depends on where the WiFi routers are located. I didn't have any issues, but your mileage might vary.
A related side note, unrelated to Starlink: if you use a VPN client like I do (I use NordVPN), the RCCL and Celebrity mobile apps say that you need to connect to the ship's WiFi for certain operations, such as making a reservation or purchasing an excursion. The other features of the app work normally. To use the app to book something, I have temporarily pause my VPN and then it works.