That "bunker" mentality is pure cult.
Just to use examples (whether the Bible is real or not, whether God exists or not) to compare:
1. When God brings destruction of the wicked by flood, God has Noah build an ark of enormous size and then gather every species of animal and food to stuff inside of it. This was not done in secret but out in the open. No need to hide or worry about opposers attacking and stopping the work. There is no need for Noah and his family to take their work "underground," even though they are in the minority. No one gets captured, no crowds of the wicked attempt to stop them.
2. God saves the Jews from slavery in Egypt in plain sight. The wicked are those that end up hiding away and suffering due to the plagues. Goshen remains in sunlight and free from disaster or attack. On the night of Passover, the Jews clearly are not hiding as they mark their homes with a display of blood. They end up being left out for recapture at the Sea of Reeds with no place to hide from Pharoah and his chariot army. But it is a trap, and God's enemies drown in the sea while the Hebrews simply walk away to freedom.
3. God redeems his people from Babylon via an invasion from an army the Babylonians aren't even aware have crossed their borders. The Babylonian kingdom topples overnight, and the Jews, without hiding, are freed to return to the Promised Land.
4. God saves the Jews from genocide at Purim after Queen Esther comes out from hiding her true identity. Jews stand ready to fight for their lives out in the open on Purim and win the victory. No hiding necessary.
5. Judas Maccabeus, instead of hiding, leads an active revolt against the Seleucid empire, redeeming the Temple from pagan worship (today celebrated as Chanukah) and liberating the Jews from foreign control. (Included in most Christian Bibles as 1& 2 Maccabees, and though not a part of the Tanakh, acknowledged by Jews as genuine but not included in the JW/and some Protestants' canon.)
In none of these situations where God redeemed his people from enemies did anyone have to hide away in a bunker. God saved his people out in the open, again and again. In Biblical fashion, the narrative is always that redemption happens never in secret but in full, public view, demonstrating God's power.