Will SmithWriting quick Steam reviews for games you like is the single best thing you can do to help their visibility. Taking 10 minutes to go through your library and bang out a handful of reviews for games with <1000 total reviews can really move the needle.
The difference between getting promoted and buried on Steam can be a handful of negative reviews. This is extra important for games that feature characters who are not cis white men. People write generic negative reviews of those games then game the meta-review layer to boost their visibility.
Normal reviews get a handful of "helpful" or "funny" tags over a period of weeks. The suspect reviews get 20 in the space of a few hours. That means that those recent negative reviews are rated "Most Helpful" by Steam, so they're shown to prospective customers first, before any positive reviews.
Reviews don't matter for games you didn't buy on Steam, so just go down your recently played games in your Library and click on the Store page button for the ones you've enjoyed. All that matters for Steam is the 👍or 👎, so if you think it has merit, a 👍 and a "I loved this game!" is enough to help.
Tacitus 🇮🇪 
That's a pity, I hardly ever actually buy games from steam these days, 99% of my library is games bought on other storefronts.
@tacitus I know. They require a purchase for them to count because review bombing is a real problem on Steam these days.