The issue with this line of thinking is we are not talking about a single forest or some minor changes to urban settings, but a massive change to the number of forests. The scale is vastly beyond adding more trees near buildings or a few more orchids. Ideally you want massive trees that live a long time and spend as much energy as possible growing larger not making fruit.
This land is not already being used for forests because other uses are simply more useful or less costly. The net loss of utility then needs to continue for as long as the carbon is sequestered.
Finally, if you want to sequester carbon somewhere else you need to collect and transport it which adds more costs. Further, if that’s the goal forests are simply slow carbon sinks in comparison to other plants.
Sequestered carbon just goes into the ground. You need not transport it anywhere. It improves the health of the soil. There is equipment that will take dead standing wood and gasify it into biochar which is stable in the soil for theoretically 10k years. These systems also produce a net positive energy (electricity and heat). Source: I wrote the firmware that runs All Power Lab's Power pallet, which does just this. It fits on a 4' pallet and can be taken to a fuel source (woodchips, corn cobs, walnut shells, grass pellets, etc.).
I'm having a hard time understanding the fundamental problem that you are bringing up. Sure, machinery doesn't just magically transport itself, same goes for the plant matter. But these machines produce fuel/electricity, so they can be used to power chippers, tractors, or whatever machinery you need to run your orchard, timber mills, or office park cleanup activities. This is the point I'm making, there is free fuel that can be used from growing plants (of a variety of sizes and uses). Just as we use lawn mowers and wood chippers to clean up our yards, we should also be using the resulting material to fulfill our energy needs and produce biochar to lock away carbon back into the soil.
You're correct, nothing comes for free, but the alternative is to leave this dead standing wood on forest floors to be later fuel wild fires. Or in the case of agricultural waste, to be composted or burned directly. Seems like a waste, as composting produces methane and CO2, which unless captured in an anaerobic digester just goes into the atmosphere and contributes to global warming, and burning does similar harm.
Small scale gasification reactors can run equipment, and are easily transported on trailers to the site of waste if it is not already easily centralized (in which case a dedicated cogeneration plant is usually a better option). A 20kW reactor can produce enough electricity to run 16 US homes, so situating one on every block is also a viable option that we should be considering.
This land is not already being used for forests because other uses are simply more useful or less costly. The net loss of utility then needs to continue for as long as the carbon is sequestered.
Finally, if you want to sequester carbon somewhere else you need to collect and transport it which adds more costs. Further, if that’s the goal forests are simply slow carbon sinks in comparison to other plants.