Yes, that was my point. Humans are not required to build vast power generation infrastructure for biomass to sequester CO2 from the atmosphere, we get it for free.

The industrial chemistry for sequestering CO2 is not that expensive in terms of mass ingredients (nothing rare or exotic), considering the scale, but it is extremely energy intensive and that is where most of the cost of sequestration comes from. If almost all of the sequestration cost is the cost of putting energy into the system then biomass has a massive cost advantage, literally orders of magnitude.

Oh, it's your mention of internal energy source that confused me, as biomass depends on external energy, just as any industrial process. And we know that an industrial process can be potentially at least just as efficient as biomass, by the virtue of same physics/chemistry.