Close the Views-to-Interaction Gap
With median views at 25,000,000 and total views at 17.95B, Mark Rober has massive reach, but median likes and comments both sit at 0.0, producing a 0.0% engagement rate versus the 1-2% macro-tier benchmark (1M+ subs).
Details
Adding explicit on-screen and verbal CTAs ('hit like if this surprised you,' 'comment your guess') in the first 60 seconds of each video would be effective, since even converting a small fraction of the 25M median viewers into likes/comments would move ER meaningfully toward the 1-2% macro benchmark.