John Gill Commentary Lamentations 5:7

"Our fathers sinned, and are not; And we have borne their iniquities." — Lamentations 5:7 (ASV)

Our fathers have sinned, [and are] not
In the world, as the Targum adds; they were in being, but not on earth; they were departed from hence, and gone into another world; and so were free from the miseries and calamities their children were attended with, and therefore more happy:

and we have borne their iniquities ;
the punishment of them, or chastisement for them:

this is not said by way of complaint, much less as charging God with injustice, in punishing them for their fathers' sins, or to excuse theirs; for they were ready to own that they had consented to them, and were guilty of the same; but to obtain mercy and pity at the hands of God.