That's true for any social deduction game. The problem specific to this game is that you need people to be reasonably creative and quick talkers whereas in something like Resistance someone can get by with just yes and no.
This is the difference that can make it more stressful. Your assessment of those who are not good at this game as not creative is the type of mentality that creates an environment that can feel judgmental. The game puts you on the spot and there is that pressure to be creative or funny etc. A person who is not aware of how people with social anxiety may not even realize this is an issue.
In a game like the Resistance, it gives you a jumping of point by giving you a position to play from but also allows the player to interact to a level that they are comfortable with.
If you've ever sat in class waiting to give a speech that you dreaded the whole time, you'll understand how it can feel to be stressed in this way. On the other hand, the Resistance is more like a discussion that you can choose to participate it at your comfort.