> So when you're designing an observability system, the whole ball game is about capturing and constraining the cardinality of that metadata.

If your world is only time series databases that struggle with cardinality, then sure. Fortunately, there's a lot more tools out there, some of which do just fine with high cardinality data.

I don't really agree much with your entire comment. I think you're looking at observability through the lens of 2010s-era tools, and falling deeply into the trap of thinking that this is the only way to do things.