It sounds like you're paraphrasing the wiki page I attached in a different comment: https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry https://en.

It sounds like you're paraphrasing the wiki page I attached in a different comment: https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemi... To address your point, I would say we are extremely ignorant about what the solution space of life looks like. Hydrothermal vents are a very recent discovery. Before this discovery, it was unexpected that such complex and large organisms could exist without light from the sun. As a planet, Earth is teeming with life. Everywhere you look on Earth, you can find it. Even though we have a good understanding of chemistry, we have little clue as to what's important to form complex and self-propagating systems.