I'd call such a cycle carbon neutral but not carbon negative. Things that are neutral are good, but we also need to figure out how to scale up some things that are truly negative.
Don't give up good in the pursuit of perfect.
If we get a few of these types of solutions - IE Growing algea to pull it from the air and burning it to get electricity and "putting it back"? If scaled? that can be the path forward - especially if we're getting electricity on both sides of the fence.
The path forward is to invent and scale and tweak and improve lots of different things.