Let's talk about aliens visiting Earth. There seems to be this issue that isn't brought up frequently in favor of discussing things like the Great Filter (which is unlikely). This is a less fun story.
Space is big. No, bigger than that. A LOT bigger than even that! Your brain can't really grasp these distances. Our closest star is still over 4 light years away. There's 41 stars Let's suppose that an alien civilization is able to travel faster than the speed of light. How long is it going to take them to travel here even if they're 50ly away?[2] Even at 10c that's 5 years. Even at 50c that's still a year! (a year is probably reasonable time, but the speed is unreasonable).
So to find alien life on Earth we'd have to have one of a few things happen:
1) Luck. Even if probability is low, there's no reason we couldn't just be lucky in having a relatively close neighbor and that they are significantly more advanced than us.
2) Alien life is extremely common. Far more common than our guesses. Not just life, but life more advanced than us! They're also good at being hidden (we can't find their radio signals despite looking specifically at these stars first. They could have just advanced way earlier and be past radio (why abandon radio?)). They would also have to either a) have pretty fast space drives (mind you >= 1c breaks our understanding of physics. See point 3) and/or b) be pretty willing to travel vast distances/spend a long time traveling (decades to generations). To travel to Proxima Centauri (4.2ly) at 0.5c you would track >3.5yrs onboard and >8 from Earth/"off ship" (~2/~4.5 at 0.9c).[3] Remember that the time "off ship" is still seen by the civilization sending the ship, so beings doing this would likely be giving up their lives at home. c) Aliens can send remote ships that either have extremely advanced AI (willing to wait years to recover that data) and/or the ability to communicate with said ship faster than the speed of light (we still have no physics mechanism for an ansible and this would break our understanding of causality).
3) There's ways to travel SIGNIFICANTLY faster than the speed of light. At these distances even 100c can be slow. This _shatters_ our understanding of physics, causality, and the universe[4]. They are ALSO able to drop out of warp being undetected (even our hypothetical FTL drives and wormholes have huge gamma signatures. That energy has to go somewhere and it is a lot of energy).
So I'm not saying that it isn't aliens, but consider that space is a lot bigger than you even thought. I don't think many people consider this aspect of space travel when they are imagining aliens. Probably because this makes for extremely boring Sci-Fis (a few do consider this, like Ender's Game, but it is not common). These distances are so far beyond what our brains were designed to understand that even our wildest imaginations don't give us a reasonably okay intuition.
[0] https://www.icc.dur.ac.uk/~tt/Lectures/Galaxies/LocalGroup/B...
[1] https://lovethenightsky.com/stars-within-100-light-years/
[2] 50ly is fairly arbitrary, but near an estimate of civilizations that would be capable of picking up our radio emissions under the assumption that they had amazing detection capabilities and could detect a very weak signal with a lot of noise (the sun produces pretty strong radio emissions)
[3] https://www.emc2-explained.info/Dilation-Calc/ (for our 50ly example at 0.9998c will get you to Earth in ~1yr on board time. Still 50 years "off-ship")
[4] https://hermiene.net/essays-trans/relativity_of_wrong.html