I always watch reviews before buying and if possible from many different reviewers. Now more than usual when stores here are still closed or online only and I can't check it myself. Even if the videos are in foreign language, at least I can see the knife from all sides and how the action is.
I'm less interested in scores and watch mostly to find out details that specs pages often don't have, like detent strength. Watching multiple reviews help to get better idea about quality and how common problems are with blade play, stripped screws, lockup or edge grind.
They aren't common, but I really like long term reviews. I don't really care if a folder can take robot arm spine whacks or hold a car hanging from it, but I'm very interested if it is still good after a year of normal use.