The quality of offsetting programs varies drastically. For example, if I just say I'm going to offset your emissions then do nothing, I can offer that service for $1EUR/ton. At the other end of the spectrum would be something like methane recapture tents over abandoned mines, where there is no risk of addition or gaming (because it costs so much to build mines in comparison to what this earns). And in the middle is something like planting trees. It's not clear where on the quality spectrum the program you're referring to is, but I would guess it is not going to be at the high end.

The other thing to keep in mind is that we are only looking at low-hanging fruit right now. That's actually one of the really appealing things about this climeworks idea. It can be scaled indefinitely. Carbon capture from mines and manure digesters can only scale so much, because there are only so many abandoned mines and only so much undigested animal manure.