It gets even worse when non-game applications use those frameworks designed for games. Like Stud.io - virtual LEGO building CAD. Even if you don’t touch the thing, it still renders 60 frames per second. Whenever I use it, the fans run high even when it is idling. And don’t even think of running this on a battery-powered laptop…
I could be wrong, but I think on a lot of complaints like that, the issue ends up being at least partially the fault of the studio using the engine being too lazy to adjust Unreal’s defaults like that. I’d be surprised if it doesn’t let you turn off rendering and preserve the current image on screen.