If we want to spread the code that users create to other people, we need to deal with the problem of trust.
Trust is needed when you can’t review the code yourself, ie if you are a simple user, or do not have the time.
Especially for UI code, I don’t think there are ways to solve this problem technically. It requires a reviewing process. I am interested to hear if someone believes that we can technically do that. My reasoning is that the way information is displayed to the user can mislead him.
For this reason, designing a reviewing process is indispensable for the increase of software diversity.