Common unifying language
Since all Romance languages evolved from ancient Latin, I would think if people wanted a common language Latin would be perfect.
What is missing in the language why did it die ?
Maybe it did not really die like all languages because of time it just evolved to something that can no-longer be called Latin ? French, Spanish, Italian ..... are all dialects in a way.
In some professions it still (probably more so in Europe). A friend of mine who is a dentist studied Latin as a compulsory part of her training. She told me she had to send a report to a French collegue. She doesn't know French so she sent it in Latin. I was really surprised that Latin is still actually used in a practical way by people outside the Vatican.