Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title

Why are movie closing credits usually animated by scrolling them from the bottom to the top of the screen? Is this because in old times there was no computer animation and the credits text template was scrolled-up mechanically by a man/device? Nowadays there must be thousands of possible ways for credit frame transitions, but still the old one is preferred.
Why do movie credits scroll from the bottom to the top of the screen?

How did another Engineer ship with a chest-burst Engineer and lots of facehugger eggs end up on LV-426 (Alien) when     all Engineers are supposed to be dead before David created the first facehugger eggs himself?   Wasn't the idea of Xenomorphs shown to exist before Alien: Covenant (2017) by the murals in the Ampule Room on the ship on LV 223 in Prometheus which might explain who piled up the bodies of Engineers on LV 223?
How to explain this in Alien and Prometheus considering Alien Covenant plot?

I've noticed a trend recently where, in a particularly violent scene, blood will end up on the lens of the camera. It's not restricted to blood; it could be water, if it's a particularly stormy scene, or mud in, say, a battle. Any kind of liquid, really. The point is that the scene is usually pretty charged.  Has this become fashionable and, if so, why? I don't recall seeing this as much when I was younger -- but maybe I just didn't notice -- and, for me, it breaks the suspension of disbelief. I presume the production team are in control of the filming enough such that they can choose if or when this happens, rather than it being accidental. Is it a meta thing to try to suggest to the viewer that the scene is so chaotic, that even the producers can't control it?

Blood on the lens

