The problem persists, as Postgres and MariaDB use incompatible SQL dialects, right down to (imo) core concepts such as how to specify an automatically generated primary key.
I'm aware of that, but what I meant is that they both extended the SQL standard in a similar way and they will have equivalent higher level features like "regex and other non-standard extensions" even if they are not 100% drop-in replacements.
Understood. My point is that the underlying concepts are consistent, but the syntax differs between vendors. This largely applies to PRQL as well. Admittedly slightly moreso, but if I already have to learn a new SQL dialect to use postgres, I might not mind learning a nicer one.