Agreed - Improving SQL should be a research focus eg new options to make it more logical such as FROM clause before SELECT clause (much better for tooling) Add Immutable options (to make it truly functional), optimize for Optane persistent memory, add native GUI/ HTML support (like Foxpro) to make it much easier to wire up IO between tables and display/input. Add NOT IN Foreign Keys.
PostgreSQL desperatly needs auto refersh and incremental Materialized Views and BiTemporal system/app timestamps.
SQL is already an incredible Logical functional language that operates at a much higher abstraction level than mainstream languages, it could be even more amazing, with not that much effort/cost relative to any other routes I can think of - to get to more human friendly, more expressive, faster, more reliable, app development tools.
Not improved SQL! Modern languages with native relational data models. Not a DSL inside a language but something native to the language and one with its normal syntax.
The ideas within SQL are powerful but the syntax would need a dust off and would need to be integrated into a modern language.
