And, given the sheer number of accents, getting the pronunciation wrong is not that big of a deal either, especially if you do it consistently. Native speakers adapt very quickly.
The real problem is understanding English spoken by those native speakers in all their accents...
E.g. “I wondered what did he do” will be understood perfectly by virtually 100% of English speakers, but will immediately mark you as a non-native speaker (the correct form is “I wondered what he did”).