Let’s preface this, I’m no astrophysicist. but from my understanding:

That’s just the thing, different speed observers do not agree on when things happen, or even the shape of the universe. The faster you go the more the universe compresses in front of you, making distances shorter from your frame of reference.

From the photons perspective it instantly moves through an infinitesimally thin sheet of universe. Everything that “happens around it” from our frame of reference all instantly happens at once if you ask the photon.

Here’s a really good explanation from someone far smarter than me https://youtu.be/-NN_m2yKAAk