Vortex is, roughly, how you save data to files and Iceberg is the database-like manager of those files. You’ll soon be able to run Iceberg using Vortex because they are complementary, not competing, technologies.
Parquet is ..fine, I guess. It is good enough. Why invoke churn? Sell me on the vision.
Mutability would be one such pitch I would like to see ...
There are other formats though that it can be compared to.
The Lance columnar format is one: https://github.com/lancedb/lancedb
And Nimble from Meta is another: https://github.com/facebookincubator/nimble
Parquet is so core to data infra and widespread, that removing it from its throne is a really really hard task.
The people behind these projects that are willing to try and do this, have my total respect.