Trees eventually rot or burn, which releases most of the carbon again. Once a forest is mature carbon sequestration is minimal to zero: https://www.sciencedaily.com/releases/2021/03/210325150055.h...
There is recent research on this that indicates we could achieve a 10 gigaton annual sequestration rate with only a 5% impact on the total terrestrial tree production and at a cost of $30/ton.[1]
"The quantity of this wood utilization can be controlled carefully to maintain a desired amount of CO2 in the atmosphere to keep the Earth’s climate from diving into the next ice age, acting as a climate thermostat."
[1] https://cbmjournal.biomedcentral.com/articles/10.1186/s13021...