Should Non-Native Speakers of English Improve Their English, or Should Natives Level Down Their Language?
That is the question

A Russian speaker of English told me he likes my podcast because he can understand everything I say.
He explained, “I have many interests so I often listen to podcasts. Many of them are in English and it’s not always easy to follow what’s being said. I like yours because I can understand it.”
English is the language of the (online) world. If it’s also your first language and you contribute to the Internet with content and ideas for an international audience, becoming more aware of how you communicate can be advantageous for everyone. You’ll engage with more people, and they’ll benefit from listening to you.
But the question is: should non-native speakers level up their English, or should native speakers level down their language? Given communication is a two-way street, both should make an effort.
So, native speakers, simplify, slow down, and avoid obscure idiomatic expressions.
Non-natives, keep learning.