Some people say that The Roman Empire - had it lasted without any Dark Age - could have given us mobile phones 1000 years ago. Some others say that it wouldn’t

Some people say that The Roman Empire - had it lasted without any Dark Age - could have given us mobile phones 1000 years ago. Some others say that it wouldn’t have happened, because they had too many slaves and cheap (or free) labor disincentivized optimizations and technology investments.