SQLite is such a great thing. Amazing value for zero cost both shmeckels and maintenance. It's a shame most startups go for postgres blindly due to "scalability concerns" it feels like a major case of premature optimization.
IMO it should become more opinionated and stricter. I'd honestly pay to buy a license for SQLite with the legacy baggage removed and rewritten to be as strict as PostgreSQL or more. Well... basically embedded PostgreSQL I guess.