When I think about it, I feel like Void being survivable is the best choice.
We already have Shadow Isles for that. Shadow Isles consumes everything too.
What is the fun of an interdimensional place being impossible to survive? I think we have so much more potential in new Void. We could have a pathfinder, or a wonder gone wrong telling us about how Void looks like and how it is. In old lore, a human would die in seconds. That's boring when you think.
Now, what makes Void primarily dangerous are voidborns. Which is better than Void energy. That doesn't mean Void energy is not dangreous and terrifying anymore, just likely it is not dense everywhere generally to immediately threaten your life.
I imagine Void now as the Upside Down of the Stranger Things series. A place about monsters, kinda parallel to our universe. Unlikely to survive, but not impossible.
Void is a definitely the more harsh one, but we know LoL characters are more capable of to do than a few kids lol.
Kai'Sa being survivor of the Void feels so much space and alien but it is in Riot style and I find it unique even though in the first I didn't like it. Only problem I am left with is how beautiful she is while she shouldn't even have and understand beauty standards.