Jesus the Divine Mercy revealed Himself to St Faustina in the 20th century and His messages to her revealed very different aspects of his Divine Mercy.
https://www.ewtn.com/catholicism/devotions/second-coming-13377 "You will prepare the world for My final coming." (Diary 429) "Speak to the world about My mercy ... It is a sign for the end times. After it will come the Day of Justice. While there is still time, let them have recourse to the fountain of My mercy." (Diary 848) "Tell souls about this great mercy of Mine, because the awful day, the day of My justice, is near." (Diary 965). "I am prolonging the time of mercy for the sake of sinners. But woe to them if they do not recognize this time of My visitation." (Diary 1160) "Before the Day of Justice, I am sending the Day of Mercy." (Diary 1588) "He who refuses to pass through the door of My mercy must pass through the door of My justice." (Diary 1146). In addition to these words of Our Lord Sr. Faustina gives us the Words of the Mother of Mercy, the Blessed Virgin, "You have to speak to the world about His great mercy and prepare the world for the Second Coming of Him who will come, not as a merciful Savior, but as a just Judge. Oh how terrible is that day! Determined is the day of justice, the day of divine wrath. The angels tremble before it. Speak to souls about this great mercy while it is still the time for granting mercy. (Diary 635)."
The mercy increased because the sins got harder to avoid, IMHO. People need daily access to the Eucharist, easily attained indulgences and a near baptismal do-over once a year just to keep up.
Maybe plenary indulgences? The yearly Divine Mercy plenary indulgence? My dear Father in law that had lived most of his life in sin with no confession benefitted extraordinarily from the mercy of Divine Mercy Sunday shortly before his speedy death. I am so grateful to Jesus.
