When I say, “bigger games” it does not necessarily mean “massive worlds”. It just simply implies that you can space things out instead of creating the typical lobby area with teleports to different places, because you are now streaming instead of having everything be persistent at all times.
Also, when it comes to streaming, it is not a “one size fit all solution”, it all depends on how you code around the technology. And when I say how well I mean knowing the stress involved for loading and offloading assets, your streaming setup because you may need to fiddle with it to get it right for your size world as well. If it’s crashing on boot that means you may not have it setup properly to load or the size of your world is just stupendously large (as large or larger than big game AAA worlds). I don’t think Roblox is ready for that right now as they are just now rolling out this by default, we are a long way away from the streaming to be improved for massive worlds. For instance, a truly massive world may need to have a smaller radius, Roblox may not be able to handle such a large radius (for viewing pleasure). Take a game like RuneScape, it’s streaming tech is probably better but the world is massive, and the radius of sight is by default a small range. You can adjust the setting to see further but by default it cuts off in a shorter range to reduce lag. All you see a black background outside the paused area, but it helped them build a massive world that can be explored without loading scenes.