To be clear, we don't have a computer that can survive on Venus, or anything near that. What the research team made is a ring-buffer, which is a collection of maybe 20-30 transistors arranged in a big circle (with one inverter).
That's a very far cry from even an Intel 8080, which is approximately 4500 transistors. And that's without any RAM, Flash, or anything else. This is an impressive milestone to be sure, but it's nowhere near an Arduino (let alone a full computer).