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.
Just to add a bit of detail re. the coal gasification. Gasification of coal, wood, municipal solid waste or like hydrocarbon sources yields a complex mixture commonly called syngas. Hydrogen is a component but the largest components are various carbon compounds, especially carbon monoxide. Hydrogen would need to be separated from the syngas. Separating the hydrogen from the syngas simply reduces the BTU value of the syngas making its BTU/pound energy value even less favorable in competition with fossil fuel fuels. I am not sufficiently familiar with the overall economics of this since the decreased fuel value of the syngas w/o hydrogen would be offset by the value of the hydrogen.
Raw syngas is a messy witch's brew of compounds. Lots of very expensive R&D, pilot and semi-commercial plants have come and gone using various methods to crack the raw syngas mess to simpler molecules to improve the gas yield and increase the carbon monoxide and hydrogen that are the best fuel components to fuel conventional energy generation using industrial scale equipment. You also have to scrub the gas to remove sulfur compounds that are corrosive and will yield sulfuric acid in the exhaust from the energy generation equipment.