Because if no one reviews the articles then anyone could publish junk. In highly technical fields the only people qualified to tell if something is BS science are the experts in the field, so they review and make sure the article has some merit.

That’s not to say the reviewing process is perfect, but it does at least help to filter some amount of bs.

You’re assuming that they scouted this and carefully planned it to ensure they wouldn’t cause damage. I doubt that.

Seems like they did:

The canvas of the painting is protected with a glass screen, a factor Just Stop Oil said they had taken into account.