I suspect that if there are alien craft here - piloted or autonomous drones - they couldn’t care less about human kind. If they were interested, they would have made their presence known long ago.
From what we can tell from our limited understanding of celestial bodies, liquid water is reasonably rare. A planet that surface is covered by 70% liquid water may be exceedingly rare. If they’re here, that’s probably what they’re interested in.
The problem is not there there is no evidence of alien contact—there are thousands of people who claim they have seen, been abducted by, spoken to by aliens.
Science calls their testimony “anecdotal” and therefore ignores it.
Is the problem with the witnesses or is the problem science and what it allows as “evidence”.