I address your concern from #1 in "2. Flexible schema - but strict when you need it" section - take a look at https://www.youtube.com/watch?v=pZkKsfr8n3M&feature=emb_titl...

Regarding #2: Clickhouse scalability is not simple, but I think Elasticsearch scalability is not that simple, too, they just have it out of the box, while in Clickhouse you have to use Zookeeper for it. I agree that for 200 nodes ES may be a better choice, especially for full text search. For 5 nodes of 10 TB logs data I would choose Clickhouse.

#3 is totally true. I mention it in "Cons" section - Kibana and ecosystem may be a deal breaker for a lot of people.

#4. Clickhouse in 2021 has a pretty good support in all major languages. And it can talk HTTP, too.