iOS-style runtime permissions (for things like location access) were introduced in Android 6.0, which was released back in 2015. That's quite the long play.
The biggest reason was that the Apollo program was able to return film from the surface of the Moon to Earth. Many of these photos weren't returned to Earth in film form. Instead they were developed onboard the spacecraft, scanned, transmitted via radio, and then recorded onto tape on the ground. Every step of that process incurs a decent bit of quality loss.
You can actually tell which probes had a reentry module because the photo quality is pretty stunning compared to the photos transmitted over radio, look at Zond 8 which returned film negatives to Earth.
The delay after taking long exposures is caused by the camera taking a dark frame with the same exposure length as your actual image. When you take a long exposure, the sensor can exhibit noise caused by "hot pixels". The dark frame is taken with the shutter closed so that the camera can get an image of just the hot pixel noise, which it then subtracts from your actual long exposure.
You can turn this off in the settings, but I imagine it's way easier for the camera to correct for this specific kind of noise than for Lightroom to do so.
I believe it kicks in once the exposure length is >2" on my Sony A7ii.