Where the like count stopped mattering, and where it never did
It is worth separating two things that get discussed as one. Instagram's ranking systems and the humans scrolling past your post both see the like count, and over the last few years they have moved in opposite directions.
On the ranking side, likes have been diluted. Instagram has said repeatedly that watch time, sends and saves carry more weight for reach, and the platform spent a long stretch testing hidden like counts precisely because the number was doing more social damage than informational good. Whatever the current internal weighting is, a like is a cheap signal — it takes half a second and costs the viewer nothing — and cheap signals get discounted.
On the human side, nothing has changed. A post with 11 likes and a post with 900 read as different objects to a stranger, regardless of what the ranking model thinks. That gap is a judgement about whether other people found this worth their time, and it is made in the moment before anyone decides to read the caption or tap through to the profile.
So a like order is not a reach purchase. It is a purchase of the assumption people make about your post in the second before they engage with it — which is a smaller claim than most pages on this topic make, and a true one.