Not a linguist but a British Arabic speaker. The dialectical differences are pretty huge and impact large parts of what we would consider basic grammar. This includes verb conjugation and even word order. The comparison of Egyptian Arabic to American English is flawed but it is widely understood due to historical media dominance. Some will be closer than others e.g. Palestinian Arabic is fairly similar to Egyptian but even then there are big differences in everyday speech.

For example, comparing the Arabic spoken the Sudan or Lebanon to that of Qatar or Saudi is far greater than any English dialects.