One of the claims in the video is that: If all of the trees in the United States (I think) were burned in these plants that it would power the United States (I think) for one year (I'm sure). Given that it takes more than 1 year to regrow all of the trees it seems like a foolish decision.

Apparently some of the plants also choose/have to incinerate vulcanized rubber (tires) to burn green/wet lumber.

Frankly, just using the documentary as my reference, this seems like an awful scheme and I can't fathom how subsidies and policy supported this technology.

Sure, but they aren't burning the lumber exclusively. If the timber is supplementing other power, then it wouldn't be depleting forests. Eg if you used 1/40th of all your timber every year, and replanted it all, you'd never run out assuming a 40 year timber cycle.

If solar, wind, hydro, nuclear, and grid storage cover most of the need, then biomass can certainly pick up some slack. And I'm sure there are plenty of industries that generate biomass as waste -- lumber, farming, etc. That waste would decompose into CO2, we might as well get some energy from it, right?

Seems like we're burning like half the trees in the us right now and powering nothing, tho.

The US has never been more forested in the last 150 years.