Can you build game without building lights?

I did a scenery the lighting was great, but after I press build, the result was… devastatingly different. Looks terrible. No matter how I adjust it I can’t get the lighting I want… was thinking can I actually export the game/ build without building the lights. I remembered I did it for an aquarium underwater environment done in unreal 2 years back without building light… if yes, what’s the drawback?

Left is after building and trying to tweak, right is original.

Well you can use dynamic lighting, set your Directional and Skylights to movable but keep in mind, performance will suffer compared to builded lighting.
A lot of games using dynamic lighting only, with Time of Day system, so it is up to your needs