Jesus gave us a heads up on this in advance.
Matthew 7:13-14 , https://www.biblegateway.com/passage/?search=mt+7%3A13-14&version=RSVCE
13 “Enter by the narrow gate; for the gate is wide and the way is easy, that leads to destruction, [ ἀπώλεια, ] and those who enter by it are many. 14 For the gate is narrow and the way is hard, that leads to life, and those who find it are few.
Then He is given a chance to reverse His position but doesn’t and instead validates and doubles down on His statement.
Luke 13:23-28 , https://www.biblegateway.com/passage/?search=lk+13%3A23-28&version=RSVCE
One could ask, why are only a few saved? Jesus said,
“because wickedness is multiplied, most mens love will grow cold. Those who endure to the end (the few) are saved. When the gospel is preached throughout the whole world, as a testimony to all nations; then the end will come.” Mt 24:12-14, https://www.biblegateway.com/passage/?search=Matthew+24:12-14&version=RSVCE
From the CCC
1036 The affirmations of Sacred Scripture and the teachings of the Church on the subject of hell are a call to the responsibility incumbent upon man to make use of his freedom in view of his eternal destiny. They are at the same time an urgent call to conversion: “Enter by the narrow gate; for the gate is wide and the way is easy, that leads to destruction, and those who enter by it are many. For the gate is narrow and the way is hard, that leads to life, and those who find it are few.”
Since we know neither the day nor the hour, we should follow the advice of the Lord and watch constantly so that, when the single course of our earthly life is completed, we may merit to enter with him into the marriage feast and be numbered among the blessed, and not, like the wicked and slothful servants, be ordered to depart into the eternal fire, into the outer darkness where “men will weep and gnash their teeth.”