Takes a lot of electricity to make hydrogen. You can do it yourself.
Get a short glass of water. Toss a 9 volt battery into it. See the bubbles ? On one side is Oxygen and the other is Hydrogen.
But not a lot of it.
That’s science fair stuff.
95% of all commercial hydrogen production is done by steam reforming of natural gas, or oil, or gasification of coal. Less than 5% is from electrolysis.