We already need carbon black, graphite, etc. This process makes production have dramatically less carbon emissions with hydrogen as a bonus. Of course we use millions of tons of hydrogen for things like fertilizer. What's not to like?

Exactly right.

Carbon black has the average CO2 intensity of almost 4 kgCO2/kgC [1] and its conventional production is so dirty and low-margin, that companies have been walking away from their plants rather than implement EPA-mandated upgrades. [2]

[1] https://static1.squarespace.com/static/5fd161c5b1bc2872873bd...

[2] https://www.ledger-enquirer.com/news/business/article2703292...