Mostly fanboys.
Brandon Herrera (gun channel on youtube) tested various rounds against a real Cybertruck door (the thumbnail is clickbait - he shoots at a real Cybertruck door, but not at the actual Cybertruck he owns).
The door actually did fairly well against lighter pistol rounds, but failed at .44 magnum rounds. The lightest rifle rounds that Brandon tested (5.56) went straight through it.
So basically a Cybertruck will protect you from light pistol rounds but that’s it.
On the following chart, a Cybertruck will protect you from the two on the left, but the other seven are going to go right through the door.
To be fair, all nine rounds will easily go through a normal car door, and out through the door on the other side of the vehicle as well. Normal car doors are not at all bulletproof.
Here is Brandon’s video if you want to see every type of round tested:
