I think you and I have a very different takeaway from the movie's message about mortality. I didn't get the things you're calling out: "makind's knowledge is false", "time is omnipotent", or "information is goodness", at least not in terms of the movie's answer to mortality. The "time is omnipotent" is a sort of "what's in the box?" reveal and the "information is goodness" is a very definite undercurrent. But in terms of the perspective on mortality, on the existential dilemma that we're all going to die, I think the key is in Morgan Freeman's advice to Lucy (SPOILER: you'll hear about this on this week's 3x3) that all life is based on passing down information. This is depicted in the opening shot at a cellular level, by the way. And it's Lucy's choice that determines the latter half of the movie. It is what she decides is the Most Important Thing. Not self-gratification, not revenge (she doesn't even kill the main bad guy!), not even self-preservation or reproduction. But passing along information. I find that a very nurturing concept, and it's fitting that earlier in the movie she reveals that the first thing she remembers is her mother's milk. I think the movie is a using that maternal relationship as a kind of metaphor. You enrich those that follow with information, with whatever wisdom you might attain, in much the same way a mother suckles a baby.
And that, by the way, is the payoff. The starry thumbdrive is just a McGuffin. Who cares. I certainly didn't. The point is Lucy's decision, not necessarily the results of her decision.
This might not strike you personally as a "mature" message, and that's fine. My opinion is nothing if not subjective! But compared to Luc Besson's other movies -- I mean, seriously, can you explain the hoo-ha at the end of The Fifth Element? -- I think it's a far more developed message. I would even argue that it's more "mature" -- that might be too loaded a word -- than what other better directors have offered. Woody Allen's "hey, let's just enjoy Marx Brothers movies" or the Coen Brothers' winking nihilism (although it's worth noting that the Coen Brothers seem to have a very deeply ingrained Old Testament BE STILL AND KNOW THAT I AM GOD worldview when they get Serious) or Terence Malick just casually marveling at the goddamn impenetrable wonder of it all. I love all those directors, but I feel that Luc Besson's point in Lucy is far more practical and less intellectually naval gazing. And I say that as a sometime intellectual naval gazer.
As for Lucy earning her powers, why do you feel that's important? Did Superman or Achilles earn their powers? No. They were accidents of their birth.
But I do think it's important to note -- and very much in Luc Besson's wheelhouse -- that she earns her powers as a result of her sex. The other mules, all men, aren't threatened with rape. But because Lucy is threatened with rape, because she's a woman, she is uniquely assaulted. This directly leads to her superpowers. That's no accident in the story. And I love how it overturns the usual threat of rape leveled at women in other movies.
However, I do agree with you that the science is dumb. If I have one more person tell me that the thing about 10% of your brain is an urban legend...