No, because I have no way to improve my ability to see loopholes and flaws, so there's always going to be residual uncertainty that can't be reduced. Risk aversion does the rest.

Probably? But I'll feel bad if I don't try to talk you out of this first.

• It's true that alien sightings, videos of UFOs, etc. are slowly accumulating evidence for alien visitors, even if each item has reasonable mundane excuses (e.g. 'the mysterious shape on the infrared footage was probably just a distant plane or missile' or 'the eyewitness probably lost track of time but has doubled-down on being confident they didn't'). However, all the time that passes without yet-stronger evidence for aliens is evidence against alien visitors.
  • You could imagine aliens landing in the middle of the Superbowl, or sending us each a messenger drone, or the US government sending alien biological material to 50 different labs composed of hundreds of individual researchers, who hold seminars on what they're doing that you can watch on youtube. Every year nothing like this happens puts additional restrictions on alien-visitor hypotheses, which I think outweigh the slow trickle of evidence from very-hard-to-verify encounters. Relative to our informational state in the year 2000, alien visitors actually seem less likely to me.
  • Imagine someone making a 5-year bet on whether we'd have publicly-replicable evidence of alien visitors, every 5 years since the 1947 Roswell news story. Like, really imagine losing this bet 15 times in a row. Even conditional on the aliens being out there, clearly there's a pretty good process keeping the truth from getting out, and you should be getting more and more confident that this process won't break down in the next 5 years.
• Even if we're in a simulation, there is no particular reason for the simulators to be behind UAP.
  • Like, suppose you're running an ancestor simulation of Earth. Maybe you're a historian interested in researching our response to perturbations to the timeline that you think really could have happened, or maybe you're trying to recreate a specific person to pull out of the simulation, or you're self-inserting to have lots of great sex, or self-inserting along with several of your friends to play some sort of decades-long game. Probably you have much better things to do with this simulation than inserting some hard-to-verify floating orbs into the atmosphere.
• There is a 'UFO entertainment industry' that is creating an adverse information environment for us.
  • E.g. Skinwalker Ranch is a place where some people have seen spooky stuff. But it's also a way to sell books and TV shows and get millions-of-dollars government grants, each of which involves quite a few people whose livelihood now depends not only on the spookiness of this one place, but more generally on how spooky claims are treated by the public and the US government.
  • There's an analogy here to the NASA Artemis program, which involves a big web of contractors whose livelihoods depended on the space shuttle program. These contractors, and politicians working with them, and government managers who like being in charge of larger programs, all benefit from what we might call an "adverse information environment" regarding how valuable certain space programs are, how well they'll work, and how much they'll cost.