Is Postgres becoming the new SQL standard? You have the ANSI SQL, but it does not cover a lot of stuff, and everyone has their own variances, and extra features.
But, all new DBs like YugabyteDB and Aurora DSQL for ditributed, pg_duckdb and pg_mooncake for OLAP, FerretDB, and Azure DocumentDB for MongoDB are either built on top of Postgres, or are Postgres compatible!