It's pretty stark. I speak Laventine and I struggle to communicate with my North African friends and often end up supplementing with english.
I'm not sure I'd go this far but some scholars make the case that the dialects are not really dialects, they are there own language that were influenced by Arabic.
See for example Taleb's argument on Lebanese being a language https://medium.com/east-med-project-history-philology-and-ge...
Historically it makes some sense because North Africa and the Laventine didn't have much in common with Arabia before Islam so they must've had their own local languages (say Berber or Aramaic) that was influenced by Arabic.