[kevindong]

As you correctly point out, everything you can do with metrics can be achieved via logs if you have enough compute and I/O. But that ignores the reality of what happens when you do indeed have too many logs to use something fancier like column store/inverted indices as you point out? I agree that in the vast majority of cases, it's likely fine to just take the approach of using logs and counting. But plenty of of developers (particularly here on HN) are in that overall small slice of the overall community that does have a genuine need for greater performance than is afforded by some form of optimized logging.

Likewise, traces are indeed (as you point out) functionally just correlating logs from multiple services which is akin to syntactic sugar. But again, that's precisely its value _at scale_: easing the burden of use. I've personally seen traces that reach across tens of services in an interconnected and cyclical graph of dependencies that would be hellish to query the logs for by hand.