A praying mantis preserved in amber for millions of years not a sculpture, but a real prehistoric insect trapped in tree resin and fossilized into a natural time capsule.
An entire moment from ancient Earth… frozen before humans even existed.
Check out : https://www.natureknows.org/2024/02/30-million-year-old-praying-mantis-is.html
Same reason CPR works right after someone drowns but not after they've been underwater a week...
You see, every cell has a "powerhouse" that turns stuff, including oxygen, into energy.
They keep a store of oxygen and food in every cell, respiration removes the waste and delivers resources.
Cut off respiration, and things start to shut down. Higher order systems first, and individual cells last.
That's why sometimes CPR works, but it took so long that the brain was deprived of oxygen and suffers damage. Everything was deprived of oxygen, but the most complicated shit needs the most and runs out first.
An insect can be "brought back" after a much longer time than a human without problems, but there's still a clock before each cell runs out of "on hand" resources and die. Whether or not decay happens after is completely separate.
For the absolutely most basic things like virus or bacteria, or even water bears, they've adapted to be able to spring back after a long time, sometimes thousands or tens of thousands of years...
But a mantis is just too complicated. Especially after 30 million years.