We have a world in the first age (think Atlantis without tech but with magic, a civilization with wealth, overflow of resources, no sickness, no pain, a civilization with more power than everyone else, enough food for everyone, never a bad harvest, never a parent or child lost to child birth, weapons forged by the gods themselves. Warriors return home from battle since the armor is invincible.), gods walks the earth, assist the humanoids in the world with different tasks in return for sacrifices and faith (the life force of the gods).
Gods and humanoids live in synergy, (Gods helps the humans thrive, humans believe in gods, gods get power from faith, power is used to help humans, full circle)
There are no evil gods nor good gods; gods are filling a purpose. God of life, grants good births and healthy children. God of death carries brave people over to the other side safe. God of harvest helps in bad years etc. God of war gives legendary weapons and armor to people. And the weave of the gods provides the magic in the world.
Now let's say that these gods someday just disappear, in an instant, something (to be decided) happens in the plane of the gods so they all disappear (since they technically cannot die). This means they no longer walk among men, no longer provide good births and strong children, no more good harvest in bad years, and dead people are no longer guaranteed safe passage to the other side. But most of all, all magic is gone, no more healing spells, no more fast travels no more than "what we would have" in a fantasy setting.
This is resulting in crops that were sustained by the gods no longer growing to the extent they might have (good crops still grow good), but bad crops dry out, get pests, fungus. Weapons are just steel, no longer imbued by the power of the gods, armor is just thin plate sheets (swords are still sharp and armor still protects, but no better than ordinary armor). People wounded are getting ill from infections an can no longer be instantly healed.
Potential other effects: Priests and Clerics are losing their offices, (might even be called frauds). People start fighting for food. Warriors who were invincible start questioning if it is worth the risk. Cities start getting overrun by wild life and other fantasy creatures that didn't want to attack before. And with reduced power of the military both in strength and numbers, that could be a problem.
Q: Would this event be enough to create a post-apocalyptic event? (Analog to fallout-fantasy)
(For reference, the story is in the third age, where the first is the golden age, the second is rebuilding, and the third is the current, haven't gotten any cool names for the ages yet.)