Broken anything is hard to understand without practice, and easy (or, easier) to understand with practice. My experience in urban US is you hear a lot of broken English, so you get pretty good at understanding it.

My experience living in Paris is that a lot of the older folks have very little practice or desire to practice speaking with broken French speakers.

Japan I found to be similar. Fuck up the pronunciation the slightest bit and you’re just stared at blankly.