> The advantage of planting trees is that we know it works, it's cheap, and we can do it right now

Here in Sweden it is the law that if you cut down a forest you replant it. We have been doing it for a century. All forests here is basically in a constant plant-grow-cut cycle unless the land is claimed for new buildings (farm land has been steady declining every year).

It is debatable if the practice is carbon negative or carbon neutral. Most of wood product do get burned sooner or later, or turned into bio gas which then get burned. Almost nothing remain as stable carbon sink. A planted forest is an future investment to be cut, processed and burned. The only exception is forest reservations and those are much more expensive to make than planting trees.

The advocacy behind replanting might be better invested into a political action of bringing similar replanting laws to other countries. Sweden mostly did it because it looked ugly to have wast areas cut down without regrowth, and because it hurt biodiversity. It also make sense economically in the long run.