Most newbie RM dev on Steam trying to sell their RTP-fested games completely misses the point when it comes to marketing.
Go to the nearby convenience store and try to find a pre-packaged breads, soft-drinks, canned coffees, and soda. They all have almost the same quality but none of them looks the same. It's the mooooost basic of marketing, heck.
Presentation, display, look, visual, style; it's the first thing people notices. You can get away with RTP if you're publishing free games, but don't expect people shelling out money if your game looks like the other one on the rack. Heck, even most big company gets shade thrown when they reused 3D models/assets from their previous games.
People should stop relying on default RTP and try to recruit proper graphic artists on their team. If you can't afford one, please take the time to find tutorials on YouTube on how to use a graphic editor and learn how to make your games visually appealing and unique.
EDIT:
All in all, no matter how delicious your food is, if Taco Bell are serving the same food with the same quality and same presentation, why would they buy yours. They wouldn't even bother to try and see if yours taste better, and if they do, your patrons won't be that much.