As was said before: The genes are already passed onto the next generation. It doesn’t matter if the parents become stupid now. There’s no evolutionary advantage to become more or less stupid at this point.
It became like it is now by some random chance(s).
IMO it depends on how much action is displayed in the movie. If there are a lot of dynamic scenes like car chases you’ll need a high rate while ‘simple’ dialog scenes can get away with way less.
That also means it depends on what movies you like to watch.
I have a really hard time distinguishing between a good 4K webrip (15-20 Mbps) and remux (40-80 Mbps), so I have no issue keeping the majority of my library encoded at ~18Mbps
That’s because Netflix and the other common services usually only stream at 6-15 Mbps. You’ll have to resort to Bravia Core or blu-ray discs to get anything in the 80 Mbps range.
Tell that to all the animals that only have one shot. There are quite a lot of them and usually they all lay thousands of eggs.
Probably the most well known of them is the salmon. Only about 5% of them survive the procreation after the salmon run (of those salmon species that actually do the run).