Untrue.
Just letting a forest grow wild is carbon neutral. The soil reaches a point of saturation. Eventually the dead trees get eaten by detritivores, releasing the captured carbon back into the air.
Keeping it sequestered long term requires burying it deep - the trees would need to be cut down and transported to where bacteria, fungus, and so on can’t eat them.

It reaches an equilibrium where it’s producing as much as much as its scrubbing at some point though.

And as it dies off it will produce more than it can scrub. All its doing is delaying the issue for someone else to deal with.