A lot of it does come to marketing, i mean, even if you aren't rich and can't pay for a big campaign, you could do trailers, talk about it on social media, send free copies to Youtubers and Streamers and spice up your store page.
For example, there is this game on Steam called Heiankyo Alien, someone just recommended it to me at one point, i liked it for the simple arcade game it is and the developer randomly contacted me just to ask if i was liking it, being that apparently so few people bought the game the guy can just talk to whoever buys it, and in the middle of the discussion i find out, oh, this game is doing relatively well in the japanese market, as in, it's become a literal arcade game in Japan:
It's a Pac-Man like game with several twists and it's gotten various versions in Japan due to being so popular there, it's kinda like Skullgirls, an indie fighting game that also became huge enough in Japan to get arcade machines.
Heck, the machines are popular enough there are exclusive modes and content that will never come to PC because not enough people bough it, western gamers ignored it, japanese gamers are playing it on arcades right now, and the Steam page doesn't mean the fact that, you know, it's a maze game that is good enough that without any anime elements or anything like that, just simple graphics, became big enough to get various machines in Japan, you'd think that would be worth a mention or two, but you'd be wrong.
Instead, the PC version is just abandoned(with a promised future mode having been announced in...2017 and still not arriving), there is no console version, not even a Switch port, and it's just lying there, i mean, the developer is still making games, but you know, they have a cool fact about this game that they never used to change the Steam page at the very least, meaning, the fact that it's good enough to become an actual arcade machine, good enough that someone paid money to make actual cabinets out of it, they don't even use "We make games that became good enough to become arcade machines in Japan" in any page of their more recent games.
I mean, i may just be bad at marketing, but i think i would put that in every page, that's actually a pretty cool thing and a great sign when we are talking about arcade-style games, or you can just complain how no one buys the game when it's biggest market is playing on a cabinet and abandon it, why the fuck not?