There comes a breaking point when the weight of wrongdoing becomes too heavy to carry, leading inevitably to total collapse. God's patience with the people's evil deeds eventually reached its absolute limit. The primary approach among commentators is that God could no longer tolerate their actions, extend His patience, or delay the consequences. His inability to continue is understood as suffering under a massive, crushing burden [מצודת ציון]. It illustrates a final state where He literally could not continue to carry the heavy load of their accumulated sins [רש״י].
The fact that the punishment did not happen immediately actually shows the extreme severity of the sin. God waited until the measure of their wrongdoing was completely full. Typically, delaying a consequence is an act of mercy. However, in the case of a severe sin like idolatry, this waiting period served a different purpose. It ensured that once the burden of sins reached its maximum capacity, the resulting punishment would strike with full force, destroying the people out of anger and wrath [מלבי״ם].
The direct cause of this severe reaction was the evil deeds of the people [מצודת ציון, ביאור שטיינזלץ]. As a result, the land was transformed into a complete ruin. It became a place of total desolation, leaving anyone who looked at it in a state of shock and wonder at the massive scale of the destruction [מצודת ציון]. This devastation was not merely a historical event; the ruin of the land remained a harsh, ongoing reality extending into the present day [מצודת דוד].