It did increase after WW2, see project sign etc., the 1940s were the beginning of everything relating to the end times, wars and rumors of war as Jesus said, the dead sea scrolls, Israel restored, computers, atomic bombs, traveling to and fro with knowledge increasing etc., “but the end is not yet” see Matthew 24:6
I believe an omnipotent and creative God could easily (and very likely did) fill up the universe with his creations, but what ever may be out there is not superior to us, we’re made in his image
However, I believe what we’ve been experiencing as ufo sightings throughout history is not physical but instead spiritual in nature and have to do with angelic and demonic warfare taking place and spilling over into the physical world and will likely increase as this age gets closer and closer to the end,
Also I suspect as we approach the 70 year mark from events in that time, that it may be prophetically significant,
I think we have while to wait for the end times. One of the verses that bothered me most from The Bible,Jesus told the people there that day that some in this generation shall not pass away until you see the second coming, not exact but that’s it just off the top of my head.
That verse really bothered me for it looked as if He was telling those people that some of them would still be alive when he returned! I found in some of the very old translations the real word used was Eon some Epoch way different than generation. Eon we have been in the age of Aquarius for a few thousand years takes quite a few thousand years to transit from one constellation to the next, so indeed look to the heavens!