It is significant for numerous reasons:

1. It retells the national narrative, from — to paraphrase — our ancestors being idol worshipers to Abraham adopting monotheism to Jacob and his descendants travelling to Egypt to forming a distinctive national identity there to being freed from Egypt to the receiving of the Torah.
2. It recounts the major story of Jewish history that set up the basis for divine gratitude (gratitude towards God for redemption from Egypt) and sets the ground work for the story of the receiving of the Torah, which is the essential text and source of divine authority espoused by Judaism.
3. It reinforces Judaism’s rejection of human deification and the crux of Judaism’s differentiation with Christianity in deliberately omitting Moses from the retelling (so that he would not be deified) and reiterating that it was “God and not a messenger”, “God and not an angel”, “God and not a Seraph”, …, “God and none other” who was responsible for the redemption.
4. It teaches the extremely important belief that we do not and must not glory in the suffering of our enemies; that, even for our enemies, we must feel a certain amount of empathy and that we should wish for our enemies to change their ways and cease being our enemies rather than wishing suffering on them. This is epitomized by the fact that we pour out wine (symbolizing the lessening of our joy) when we recount the ten plagues and the suffering of the Egyptians; despite their oppressing us and killing us, we are nevertheless to show empathy and not celebrate their suffering.
5. It provides an immersive experience that naturally leads to question-asking that is ideal for communicating the history of Judaism and numerous laws of Judaism to the next generation.
6. It is a mitzvah (divine commandment) ordained in the Torah and is one of the three annual pilgrimage holidays commanded in Judaism.