If the game developer wants to follow a particular marketing plan, e.g. they've discovered they get more sales when there's a lot of positive Steam reviews, then of course you can help with that. If retweets, or Reddit posts, or Facebook likes or lets-play Twitch streams, or whatever else sells copies, and you're in a position to do that...
However, when buying on Steam, you need to watch out for your own interests too. Will you still be able to play this game in 20 years? Checking there is a crack is your insurance policy.
If you can buy it DRM-free on itch.io or GOG, do that instead. Steam store pages will list if there is any _third-party_ DRM, but won't list if the developer is using Steamworks DRM, so generally you have to assume it is (unless the developer assures otherwise, or it's on https://www.pcgamingwiki.com/wiki/The_big_list_of_DRM-free_g... )