Buying backlinks: relevant. Blog comments: very outdated. Original data and research: very relevant.
Digital PR: very relevant. Keyword stuffing: outdated. Give an answer in the first 100 words: very relevant now especially.
Page speed: relevant if it's actually slow; most of the time, outdated. Topical authority: very relevant. Chasing one keyword: very outdated.
You've got to own a topic now.
Good reviews: relevant, especially if they have descriptive information in them. Domain authority score: outdated. Domain authority score is just an external signal, guys.
Do not focus on this.
Follow for more information on how to come up higher in AI search.