The home feed is a place with endless updates. Depending on how many people you follow, swiping down to refresh the page could give you a whole new set of posts from them - even if you do it over and over again.
In other words, all those posts are competing for the user's attention. If it's interesting, then great, you'll get the interaction that you hoped for. But if not, then you'll risk being swiped and skipped.