You are aware that "temporarily" in this context is the lifespan of a tree, right? Trees live anywhere from several decades to 20+ centuries, and their remains, once broken down, provide nutrients to the soil so more trees can grow.
Hence why you need to cut them down and bury.
And, BTW, trees don't stop growing. They keep adding mass in their trunks. Literally the first google hit for "do trees stop growing": https://earthsky.org/earth/what-makes-a-tree-stop-growing
Edit: guess what? They even grow faster as they get older! https://www.npr.org/2014/01/16/262479807/old-trees-grow-fast...
Anyway, the land we have is limited. You literally can't cover the planet in one big forest to capture the gigatons of carbon we have released. You have to do active forest management and store the carbon somewhere stable, for example as biochar.