Just got off a cruise and there were two babies on the ship. From what I could see they had a whale of a time and were absolutely no trouble to the other passengers as both had parents who were attentive and caring.
Eating in the Colonnade or Patio was not an issue with the and there were high chairs available. I saw one set of parents in the MDR at night a couple of times and they appeared to have an app on their phone that allowed them to leave the baby in the suite and monitor from the bar or restaurant. Have to say with the attention they paid to the child they must have been tired out so an early night may have been just what they wanted.
Room service, in room bar, TV with loads of films, what more could you want. If your cruise is in a warm climate, an evening on the verandah listening to the waves, watching the moon with a chilled bottle of wine. What more could you want. Remember room service delivers the MDR menu when Dining Room open.