The projects you've mentioned are attempts to address stream processing needs with a SQL-like language. That is fundamentally different from providing incremental view maintenance of actual SQL using streaming techniques (what Materialize does).

If you want to maintain the results of a SQL query with a correlated subquery, StreamSQL in Aurora did not do that (full query decorrelation is relatively recent, afaiu). I have no idea what TIBCO's current implementation does.

If you want to maintain the results of a SQL query containing a WITH RECURSIVE fragment, you can do this in differential dataflow today (and in time, Materialize). I'm pretty sure you have no chance of doing this in StreamSQL or CCL or CQL or BEAM or ...

The important difference is that lots of people do actually want to maintain their SQL queries, and are not satisfied with "SQL inspired" languages that are insert-only (Aurora), or require windows on joins, or only cover the easy cases.