It is anything but lightweight. It's a full Chrome browser that struggles to show even the most basic "text with images" pages and hides useful functionality in corners while pestering you with multiple CTAs
It's actually an Unreal Engine 4 application, that only displays an Unreal Motion Graphics UI, that only contains a single Web Browser widget, that may or may not be chromium. Also its PresentInterval is locked to 2, so it'll never go over 30 FPS. Fun times!
Right now I have open:
- 2 Rider backends with 8 and 7 GB of RAM consumption, plus rider64.exe with almost 4 GB of RAM usage.
- UnrealEditor.exe with almost 1 GB of RAM usage (6 GB committed).
- Firefox with 500-ish MB of RAM usage.
- Epic Launcher with 500-ish MB of RAM usage.
- Steam with 200-ish MB of RAM usage.
The launcher seems to be the least of one's problems when working with UE, resource-wise.
Though my experiences modding various games with their unreal 4 dev kits were much worse. Especially coming from modding games with engines where you could edit scripts with the text editor of your choice.