This is the crux of my point. Postgres is the solution in question of the article because I simply assume the majority of companies will start with Postgres as

This is the crux of my point. Postgres is the solution in question of the article because I simply assume the majority of companies will start with Postgres as their first piece of infra. And it is often the case. If not - MySQL, SQLite, whatever. Just optimize for the thing you know, and see if it can handle your use case (often you'll be surprised)