My biggest refererer site is Reddit: 125 from posts on the few subreddits which doesn't auto ban you. From itch my profile page: 22. Other Itch refereres are less than 10 or so. Posting on Discord, YT and X (have 3000+ followers), doesn't lead to any traffic.
So, I guess that supports your explanation, that Itch is mainly a hosting site, basically.
Seeing Abyssal Ascent being more visited and played than the other games, I wonder if that is due to the image could look like ingame graphics, and the other thumbnails doesn't look like ingame graphics. So maybe there is a takeaway there?
Downside to this is a consideration whether it is worth investing countless hours in making free "presents", if no one bothers to open them.