How this compare cost wise to other solutions for carbon capture like planting trees? Looking at its cost per ton of CO2 it seems quite expensive for a normal consumer trying to go net-zero.
Planting trees is anywhere from very good (cutting the trees down and burying it so deep it doesn't rot back to the atmosphere) to very bad (the tree doesn't grow or burns in a fire, effectively adding CO2 equal to the cost of planting).
There's other not good (carbon-wise) uses of trees, like harvesting for firewood, or culling to prevent the spread of diseases like oak wilt or bugs like the emerald ash borer.
Compared to chemically weathering minerals, trees are at best a gamble. Most people aren't stuffing dead ones in really deep holes; the best we can hope for now is they get cut up into quality furniture or building materials that will last decades or more.
There's really very little long-term upside to randomly planting trees and hoping for the best, aside from the fact that trees are really nice things and intrinsically good to have. Just not a super effective carbon sequestration scheme by comparison.
Forests will typically grow for years-decades, and absorb carbon dioxide throughout, till their biomass (per km^2) reaches an equilibrium point. At that point the forest will go from a carbon sink to carbon neutral (averaged over several years to account for forest fires and subsequent regrowth).
Estimates of the carbon sink per km2 are about ~200-400 Ton/km2/yr or ~2-4 Ton/ha/yr (Slope of curves in Fig 7 in https://www.nature.com/articles/s41598-021-99395-6) To absorb our current 10 GTon C (~30 GTon CO2) we would need ~30-50 M km2 of area; Arable (crop) land area is ~15 M km2 (~10% of Earth's total land area) and grassland is ~30 M km2. Clearly we aren't going to turn nearly all of arable/grass land area to forests, but vegetation management could be a significant part of carbon management.