Is having a speechwriter unique to the U.S.?

People seem upset about the recent plagiarism related to Melania Trump’s speech, yet nobody seems to care that the alleged plagiarist is Melania’s speechwriter who stole some lines from Michelle Obama’s speechwriter.

This is theater, yet it’s presented as an essential part of a functioning democracy. Why are we ok with the concept of the speechwriter?

How can people feign outrage at the apparent plagiarism? And how is this different from arguing about the actions of a person on your favorite “reality” tv show?

Are other countries subjected to the same theater? Are their leaders just performers who read or have memorized their lines?