Ive played 2.5k hours on NA East, I've had some of the worst times I've ever had in my gaming career. 0 team work, 0 brain function, toxicity of blaming others before themselves(all though still happens it's wayyy less then NA) is wild.
I play EU for 2 days and have had the most fun and insane comebacks I've ever had, more people speak English and there's WAY less "gg end mid" after dying ONE time. I highly recommend staying away from NA, also I've heard sea is the worse then NA so I can't even imagine what that's like.
NA really is terrible, no one knows hero limits, no one knows how to play aggressive, and no one knows how to capitalize on a lead, no one knows how to look at their own gameplay and realize what they did wrong and how to get better. Never will I play NA again
Source: https://www.reddit.com/r/DotA2/comments/uuh7p8/the_difference_between_eu_and_na_is_almost_unreal/