TLDR, you're right. Here's the math to prove it.
I did some research into this a few years ago. Here's what I remember. Most of it is easy to search for to verify, just slightly time consuming. Broad brush strokes here to get you started.
Your average "big" tree (oak, pine, maple) will absorb about 10-20 pounds of CO2 every year once it's about 10 years old, on average. Lots of variables obviously. From what I saw, and there's debate, but the rate of CO2 absorption doesn't seem to speed up as much as we'd expect as they get older. I don't know how true that is, but at the same time, I could never find hard numbers to disagree. I have to work with what I got.
According to the US Forestry, per acre, you can have 100 really big trees or 500 really small trees. The problem with higher density is the increased wildfire hazard. It was something like 150-250 trees is the most they like to manage an area. This allows enough space to slow fires and ability to easily clean debris (if it's a managed forest) to choke out the fire.
For this, let's say we want 150 big trees per acre and on the best case scenario, once these trees are 10 years old, they're sucking up 20 pounds of CO2. That's about 3,000 pounds of CO2 being absorbed from the air with the hopes and prayers that a wide fire doesn't come through and undo that work.
Back in the day, I did this to figure out how bad Bitcoin was to the environment. Let's do Ethereum since NFTs are so hot right now: https://digiconomist.net/ethereum-energy-consumption. Every Ethereum transaction puts out roughly 29 kgCO2 (63lbs). That's an energy usage that truly never has to happen, but does out of vanity for the idea of saving the world from the 1% so it can create a different, new set of 1%ers. I'll get off my soap box now. That's 3, 10 year old trees needed to be carbon neutral for the average Ethereum transaction. Bitcoin is far worse, 367kg(800 pounds) per transaction. That's 40 trees needed per bitcoin transaction for carbon neutral. According to https://bitinfocharts.com/ethereum/, there were 49,000 Ethereum transactions yesterday, 250,000 for bitcoin (same site). So that's 147,000 trees or 980 acres of 10 year old trees needed to be planted every day to offset Ethereum. 66,666 acres, per day, to offset Bitcoin. Hopefully a wildfire doesn't come by and fuck up everything. Forcing you to replant to catch up on an amount of space that's incredibly unrealistic. Not to mention the CO2 of the logistics to move that many personnel around to plant that many trees.
Moral of the story, you're right. The impact of planting a handful of trees is shit. And don't get me wrong, I think we should be planting trees and trying to bring back forests. Rehabilitate destroyed and distressed ecosystems is a fantastic idea. But let's not suck each other's dicks that we're going to save the planet with YET ANOTHER PIECE OF DIGITAL TECH that is "going to solve the world's problems". Go buy a fucking tree, some seeds and a shovel. Get off the computer and go get your hands dirty. Anyways, it's far better to just cut the bullshit out of the planet instead. I just focused on the 2 largest cryptocoins. They're a drop in the bucket compared to everything else, coal, gas, etc. Cutting the CO2 producers will do more than you can realistically replant.