PostEaseImpressions are a starting point, not a result
An impression is counted whenever a post appears on someone's screen, regardless of whether they engaged with it at all. A large impression count with little engagement underneath usually means a post reached people without genuinely landing.
Watch how long people spend with a post
How long someone stays with a post is weighted heavily in the ranking: reading it, expanding "see more," watching an attached video. A post that earns a lot of time spent does more for an account than one that earns quick, passive likes.
Judge comments by quality, not just count
A handful of substantive comments reflects more real value than a large number of short, reflexive ones. Engagement-bait tactics designed to farm comments are now actively worked against, so a high comment count earned that way may not show up in reach at all.