It's funny for me that this sort of application is largely rooted in fossil fuel extraction to work (though I don't write it off because of that). Helium is trapped in the same geological formations that trap fossil fuels so you generally extract them together. Hydrogen similarly is currently made from fossil fuels if you wanted to instead use that. Doesn't mean I think hydrogen based balloons from electrolysis is nonsense or that it's a bad use, but it is funnily ironic tech.