We have been on four cruises on Royal Carribbean and loved it. Although we never specifically looked for wheelchair accessibility, my recollection is that several banks of elevators serve every deck and the gangway would be easy to traverse. Remember, many passengers are senior citizens so the ship has to be easy to get around.
How is it getting off the ship and experiencing the local environment?
I’m making an educated guess in thinking that most Carribean towns are less than wheelchair friendly.
And to be fair, I’m a real PITA when it comes to wheelchair access and all that. It comes from years of experience. ;^)