Load scene or enable/disable?

Hi all,
I was watching some unity tutorial and found a concept which looks strange to me and never used it actually. When player needs to move to another map we load another scene , correct? But in above tutorial they are loading a SINGLE level (empty one), then create first level, group all first level assets in one scene folder, then disable fcene1 group (scene seems empty again), then they add scene 2 objects, group them, disable etc. So when they need from scene1 move to scene2 - they simply disable scene1 folder and enable scene2 folder etc.
Have anybody ever used such approach with Unreal? On one hand it may seem handy, but keepeng everything in one scene, even if it is well organized seems bad way to me. Not taking into consideration loading time of such level and it’s sizes. I doubt this approach can be used with huge maps. Anyway, anybody tried this with UE?

The key word is level streaming where you can load maps in which contain whatever you want to load in and out. You will need to make a persitent level which contains stuff you normally don’t want to unload, like reflection captures and other stuff. You can trigger it by boxes when walking in or in blueprint with “should be visible”. Hope that gives a little impression.