It seems insane that we aren't looking at trees more seriously. Here we have a self-reproducing, exponential, solar powered, organic, low-tech, carbon capture system. We don't even have to plant them, we can simply allocate land and let them do their thing on their own if we're patient for natural succession. Or we can accelerate the process by planting select species, thinning etc.
We should also be setting aside more of the remaining old-growth forests to protect them from being logged, as these forests represent a standing carbon sink (aside all of the other ecological benefits of protecting old-growth forest).
I know it's not the complete solution and that we need all the cards on the table, but I fear that in our appetite for high tech fixes, we're overlooking this simple biological solution.
As others have said, trees are only temporary as they eventually die and need to be replanted. They're also slow to start, and need to be maintained (which costs carbon as well).
That’s pretty much how we got here, except instead of planting we mined, cut and burnt.
The pathway back is rather harder.
The problem is the space issue and that it takes a decade or two for there to be meaningful carbon uptake.
Most land is private so you can't go around planting willy nilly. What's worse is that you are technically not allowed to plant on most public land either, although for small amounts of native species, you can sneak by.