the best CO2 capture are trees

Probably algae.

Land only slightly beats the ocean, like a 53-47 split or something, and trees are only part of the primary production on land: https://en.wikipedia.org/wiki/Primary_production

This is also why you sometimes see startups pumping green goo through plastic pipes for home-scale solar biofuel systems.

They are good at capture, but not sequestration.