Multiversal Brainbending!

Steins;Gate is an anime series I had heard of. After finally getting around to watching it, it proved not what I expected. I knew it was some sort of time travel tale, but expected more action. Some of what I had read implied some sort of struggle between factions of time travelers. Instead, while there are, at times, more than one faction in control of time travel devices/methods, the story really only follows one group. It's much more psychological than action-packed. The first half of the series is slow, establishing relationships between the characters and "rules" to what they can do with their time travel machinery.
For that, it's pretty good. Not all my questions are answered by the end, but it does a reasonable job of consistency between the various screwing up and attempted repair of timelines. One could argue that the story really only follows the main character as he bounces between parallel worlds (or "world lines," as the series puts it), though there's indication it's more than that, too.

Then in our other multiveral entertainment, the Lords of Gossamer and Shadow game, our intrepid little band is hailed by someone claiming to be from an alternate Grand Stair.
It's a little thing, but the implications to that are pretty huge. And, to me, wearying. Already, you have Gossamer Worlds, which can be functionally infinite (or they could be a single city, potentially). Then you have the Grand Stair, which connects all the Gossamer Worlds, giving PCs access to a virtually infinite number of settings. Now there's more than one Stair as well? That opens up the door to a potential infinity of infinities of infinities. Just as a concept, it starts to feel silly pretty quick.
But one of the things I've most struggled with is finding some sense of "reality" in such a game setting. When there are infinite worlds/options, none of them really matter. Stopping World War III in one Gossamer World is pretty pointless on the scope of a Warden or the Stair itself because one Door over there could be a world in which is happens anyway, and on the other side a world in which is was stopped without intervention. When all Gossamer World possibilities are equally real, they carry no weight to someone who can traverse between them.
Which is why the Grand Stair provides at least some sense of "reality" holding it all together. That seems important to me. Wardens might have infinite doubles, but they could potentially be "unique" in their ability to step beyond the Gossamer Worlds.
And now, apparently, even that doesn't exist. I mean, I suppose as long as the PCs can't cross between Stairs, then there are still Stair-unique stakes. But it feels like yanking out the basic reality from under them...