Why pirates are called pirates English jokes

Due to cultural differences, the joke "They are just arrrr" is considered by Americans as "the best joke ever". Why do they think this is the best joke?

-this is the arrrr, which is actually the "long tongue" of are. Pirates need a pirate accent, and this R-shaped tongue has always been a major feature of Hollywood pirate movies. Over time, it has become this phenomenon. When it comes to the word arrrr with distinctive pirate color, you don't have to think much about it, which means pirate.

This is my opinion. It may be difficult for people in China to understand this joke.