It has many benefits. Many. At least if article is correct. Doesn’t burn. It allows for energy storage which is huge when you take into the account renewable energy generation. It might even allow you to store surplus at home. It’s less weight which results in less consumption.
Also what makes you say that hydrogen failed. AFAIK perhaps for cars is not viable right now, but for bigger vehicles it might be very convenient.
Edit: also doesn’t require huge improvements of energy infrastructure.