Usually it’s neither — it’s whether people can find the page at all 🎮
Two numbers off my own page, small sample (53 attributed visits over 30 days), so treat it as a shape rather than a law: itch search 32%, tag and browse shelves 17%, forum threads 15%. About half arrived through itch’s own search and browse on days I did nothing at all, and the part that felt like work was the smaller share.
The highest-return afternoon I have spent on this project was not a trailer or a post, it was rewriting tags. You get ten slots, most pages fill about four, usually with words describing the setting rather than words a stranger would actually type. Every tag is a shelf with two listings: Popular, which a new game cannot win, and Newest, which it can — and Newest is where people browsing a niche look. Cutting three tags that did not describe the game and adding accurate ones put mine top of Newest for its main tag, and nothing else about the page changed.
Worth separating before any of that, though: are people finding your page and leaving, or not finding it at all? Views against plays/downloads tells you which, and the two fixes point in opposite directions. Which one is it for you?