I cannot talk for the whole industry, but I know for sure, that I (working in BigData / OnlineMarketing) was looking for exactly this recently: A BI tool that is agile and a database that is fast. I ended up with Tableau Server and ClickHouse (which is impressivly fast). Problem was: Tableau does not really support CH and Tableau is not that agile. So to answer your question: Yes. If QuestDB is that fast, there is a demand.
JFYI SeekTable already has a connector for ClickHouse :) it works over native binary protocol (with connection-level compression). Since you have control over SQL query and SQL expressions used for dimensions/measures ClickHouse SQL-dialect is not a problem.
