David had a lot more numbering and statistics going on in the Bible than we alluded to earlier.
(8) Tu mets devant toi nos iniquités, Et à la lumière de ta face nos fautes cachées. (9) Tous nos jours disparaissent par ton courroux; Nous voyons nos années s’évanouir comme un son. (10) Les jours de nos années s’élèvent à soixante-dix ans, Et, pour les plus robustes, à quatre-vingts ans; Et l’orgueil qu’ils en tirent n’est que peine et misère, Car il passe vite, et nous nous envolons. (11) Qui prend garde à la force de ta colère, Et à ton courroux, selon la crainte qui t’est due? (12) Enseigne-nous à bien compter nos jours, Afin que nous appliquions notre coeur à la sagesse.Psaume 90, Louis Segond Bible
David complains here of general vice, a persistent reduction in life expentancy, a poor economy, net emigration, rampant lawlessness, stressful living situations, and heart disease, all of which had been taking a heavy toll throughout the population of the Kingdom of Israel during David’s reign.
People were sitting on their butt and numbering their own days, without even “applying their heart” in the sense of getting sufficient cardiovascular exercise to prevent premature death.
David was ruling a third-world kingdom, and he had to go to war to improve the standard of living, not just in a monetary sense, but in the sense that because of the compelling effects of vice, people were no longer free (as they were at the time of the Judges) to make and live by their own decisions.