Let's keep discussion bar high.

I've just checked their website, and they state "relying on ClickHouse to power these analytics use cases". That's not OLTP. https://clickhouse.com/comparison/postgresql

Fair to say, seeing 1000x w/o any trace of proof won't help me to choose.

You new to the world, right? ClickHouse proven being a beast for analytics, tracing and even some basic metrics storage (VM won of course, but still CH is probably 2nd or 3rd)