It's a tiny factor in most cases but it's there. I am prejudiced against Bethesda's janky engine no matter how much they polish that turd it's still a turd in so many ways, and I also consider Unreal Engine a cautionary flag to remind me I need to check if the game's performance is horrific. Not really UE's fault itself, but developers love that they can easily turn on all the AAA eye-candy features without having any of the knowledge or understanding of how to optimize their game (or frankly the budget) to support those performance-intensive features properly.