Well, I don’t know. Like Einstein, I believe in infinity because I believe in God and He has no beginning and no end. As far as time goes, maybe you could call that “macro infinity”.
Here, we’re talking about something more like “micro-infinity”. Maybe our numbers and math can only take us so far. It’s probably in a dimension beyond our three-dimensional universe. I suppose in that sense, maybe you are right that it may not “physically” exist, at least in our three dimensional universe. Maybe it’s like trying to come up with an equation for a black hole.