Henry had no idea that his own quantum computer had calculated the decay-rate algorithm, something related to the birth of The Lizard. Even if he had known, he would probably have felt like giving up anyway.
Doctor Octopus was like that, and so was Hulk. The world would become what it was meant to become, so let it be. All he could do was give things a shove when the overall situation hung in the balance, speeding up developments or tipping them toward one side.
Like the war against the Vampires currently raging in full swing, or, further back, urging Tony Stark to investigate the truth behind his parents' deaths in that car crash. He had merely gone with the flow in all those matters, without much effort.
How much effort would it take to stop the tide of history or prevent certain people from being born? Rather than do such thankless, exhausting work, he might as well play blind. Was he really supposed to take the rise and fall of Earth as his personal responsibility?
His outer shell was Kryptonian, his insides belonged to a transmigrator, and his homeland lay across the ocean. He had no sense of belonging to this damn world at all. So what if The Lizard showed up? As long as he did not prance around in front of him and become as much of an eyesore as the Vampires, it was fine.
Once those supervillains appeared, the corresponding superheroes would naturally deal with them. Unless this was some messed-up universe destined for a future where the villains won.
If that day really came, he would deal with it then.
For now, aside from taking care of the old folks, his most important task was keeping his own stomach full.
Although a Kryptonian's digestive system