Steam is gross, popularized the “own nothing” model (along with loot boxes), and just has a bunch of (very passionate) fanboys because it’s the least gross option (barring gog, which they often conveniently ignore), but this is more a problem of publishers consolidating and buying studios, giving some games obscene marketing budgets. The overwhelming majority of games are released by people whose marketing amounts to making (not promoted) social media posts on an account no one follows. Meanwhile Ubisoft, Microsoft, take two, etc have the capital and connections to dominate the press, social media, YouTube, etc
Best game ever won’t make a dime if no one knows about it. Even if you can get some pull it’s hard to compete with the game that everyone is talking about. That game is also probably more expensive, which theoretically gives you an edge, but in practice much of the time probably means your game isn’t getting purchased if the consumer is also hyped about gta6 or whatever
One measure they could take is to significantly lower or even eliminate their cut for niche games. They currently do the opposite, the largest cut (30%) comes in until your game makes 10 million, then progressively gets lower (25% 10-50m, 20% 50+m). A lower bracket that says like, 0 to 10% if your game makes under 300k or whatever. Based on this article they clearly make the majority of their revenue from heavy hitters so this would barely impact them