We all know it's nonsense if you compare social science/humanities fields with STEM. ? It's always harder to get into STEM fields than communication. Don't know if communication has lower acceptance rates, but if that's the case then probably it's a function of funding: engineering departments have more funding for students, so they can have higher acceptance rates. If that makes sense.
Also, some communication departments may not give you guaranteed funding, but you can still get funding outside the department but still within the university. This is a more difficult route, of course. For example, you can get an RA or TA position in, say, Anthropology or Sociology, or a project assistantship in non-academic institutes that would waive for your tuition, provide stipend, insurance, etc. So there are actually a lot of choices within the university, and the department that admitted you but didn't give you funding is likely to help you access outside resources. Again, this is a hard route, but fairly doable for those who really want to get into that department for "super compelling" reasons (i.e., you only got accepted to THAT department, so you don't have "so many great options").