Quote: "So maybe I was wrong and we are already at a point where games can skip making cut scenes (though I still think they have a purpose such as being used to hide loading times)."
You can load asynchronously in the background, entire levels and scenes can be loaded and unloaded into
existing levels/scenes on the fly, streaming is nothing new nowadays and how you achieve infinite open procedural worlds . You can do it by 'slicing into grids and loading/unloading neighbour areas or as I said above even loading areas and scenes directly into existing ones.
Hacked this for a Reloaded comp entry where entire areas were hidden and shown using triggers but it was just that....a hack workaround using entity id numbers.
Without proper manual control over sectors and portals and no background loading and unloading you will run into problems with memory limits as all the game media is constantly loaded from the start so streaming is the way to go. If your using levels you really don't even need cutscenes to hide the load time since the engine started loading this up and dropping out the old one several seconds ago in the background and the cutscene is merely a story vehicle and not a method of concealment as it used to be in the olde days.
Depends on how large the levels are but with clever design you can do this easily and load times are non-existent.
Sometimes you got no choice and require a cutscene to hide if loading a very large area, games like Witcher3 do this when you 'fast travel' as your literally dropping out an entire level area and loading up an entire new one on a button press so there is no time for asynchronous loading, but for games that don't use 'fast travel' everything can be fairly continuous and fluent and the world can be 'infinite'.
Of course static and dynamic batching of assets can help immensely with performance and memory load too, but unfortunately is another thing you are unlikely to see in GG, though it is a required feature of 'other' engines. Couple all this with proper frustum and occlusion culling and you got blazing fast games.