Those are all capturing CO2 from the waste gas stream at fossil-fueled power plants, so it's not really relevant to direct air capture of CO2 from the atmosphere.
One big problem with using fossil fuel exhaust as the input stream for productive chemistry is that there are lots of fuel contaminants - sulfur, etc. - that poison further chemical reactions on the CO2 stream, and stripping out the contaminants is just too expensive. While atmospheric CO2 has a big concentration step, it has the great benefit of not having that issue.
One big problem with using fossil fuel exhaust as the input stream for productive chemistry is that there are lots of fuel contaminants - sulfur, etc. - that poison further chemical reactions on the CO2 stream, and stripping out the contaminants is just too expensive. While atmospheric CO2 has a big concentration step, it has the great benefit of not having that issue.