Compared to what? Economically viable is very vague and relative. Columnar storage can easily reach 90% compression levels, is faster to read, and vectorized processing beats per-row/record iteration, so there's a reason it's the best for OLAP currently.
Why not benchmark IronDB against Clickhouse and post the results?
Both of you commenters have your own TSDBs which seems to be coloring all of your posts.
I'm going to leave this conversation as unproductive unless you care to benchmark your products against modern column-stores, although I think it's telling that there are never such benchmarks available.