There are other models as well eg datalog, but popularity is a factor of many things — a major factor with databases is that historically the engine is far more important than the language; you would expect users to choose an engine, and whatever language came with it. Which implies that the decision is on the producer side, not the consumers.

Which finally implies that usage popularity is not adequately explained by user preference, because you wouldn’t expect user language preference to have significant impact on the decision making process.

But regardless, are you also going to claim that C, Oracle, IBM, Microsoft, etc were optimal in their respective fields, during their respective eras, because they held total market domination? Incumbency is one hell if a drug..

Bandwaggoning and deffering to the status quo is not argument for quality; there are too many factors involved beyond quality itself. Fixable flaws in the language have been pointed out and not been addressed in this conversation chain. Alternatives languages exist, both academically and practically; they don’t come alone. Its not a competition in a void, the ecosystem has to move together. This occurs in every aspect of tech (did you ever wonder if there could be an OS other than unix and window styles?).

Asking why SQL was never beaten out in popularity is a hugely different question from whether there can be a better language than SQL, with largely unrelated amswers(Oracle/IBM were hardly fair players in anything they did)