Most people who learn Chinese will never be able to sound Chinese. To Chinese people they will look like some fool who has learning deficits (I know this is not true, but the lack of empathy in mono-cultural nations is quite high). I don't think there's any language in the top 20 most popular that punishes you as hard for incorrect pronunciation. While in English having an accent is quite common and charming, in Chinese bad pronunciation will make things incomprehensible.
For Japanese on the other hand I have multiple friends who after a couple years are indistinguishable from natives. The pronunciation system in Japanese is super easy in my opinion. It's almost a subset of the English language.