“Falsifiability or refutability of a statement, hypothesis, or theory is an inherent possibility to prove it to be false. A statement is called falsifiable if it is possible to conceive an observation or an argument which proves the statement in question to be false. In this sense, falsify is synonymous with nullify, meaning not “to commit fraud” but “show to be false”.
For a statement to be questioned using observation, it needs to be at least theoretically possible that it can come in conflict with observation. A key observation of falsificiationism is thus that a criterion of demarcation is needed to distinguish those statements that can come in conflict with observation and those that cannot (Chorlton, 2012). Popper chose falsifiability as the name of this criterion.”
The point of falsifiability is that it gives us an objective standard by which to measure the truth value of a concept.
We don’t need to rely on your subjective assessment that Martians are unlikely, which is just as well because many people will tell you that it is unlikely that little green men haven’t visisted Earth. Whether these things are likely or unlikely depend entirely on your starting assumptions.
The point of falsification is that it prevents us from misleading ourselves, albeit unintentionally or subconsciously.