This was was pretty interesting with nice animations "History's Most Powerful Plants" (
https://www.youtube.com/watch?v=9pLQwa6SyZc), but it's more presenting conclusions and theories of mechanisms than how those conclusions were arrived at. I recall hearing similar things without such nice imagery or focusing on a particular plant as a kid but where's the adult explanation that has all the caveats and messy parts of the story that don't line up and all that. I've never seen or heard that part.
They mention certain bacteria not being present to breakdown the plant matter of that special tree, but what about fungus, I would think fungus has been around a pretty long time. There's something very hand-wavy and too tidy about it all. I guess one thing is known is that these are carbon based materials and where does carbon primarily come from and how did it get way down in the bottom layers of the earth is a big question. I think today we'd identify the atmosphere, but it would be surprising if it was the other way around, if carbon mostly came from the earth and got released up as CO2 somehow. But CO2 is very stable, I think we'd expect the dominant source of an element to be all bound up in its most stable forms.
I'm curious too how deep down do oil wells go. This hit has some fascinating real world depths apparently.
Hydraulic fracturing reaches depths ranging from 5,000 feet to 20,000 feet.
https://www.petro-online.com/news/fuel-for-thought/13/breaki....
I'm curious next how much oil can be extracted from a well and how we could back track to that being some percentage of some originating mass and if the two things match up to some realistic numbers with our experience for how much mass one finds in a forest today, etc.