Maybe the purpose would be to have a portable fuel with high energy density that is backward compatible with an enormous installed base of existing vehicles, fueling stations, etc.

> there are tons of minerals we use that are of limited supply

If asteroid mining becomes a reality, it's not

> non-recycle once used

I'm no chemist, but it seems that if the economic need is great enough, with only energy you'd be able to melt / vaporize just about anything and separate the atoms by mass with centrifuge.

Well, maybe not helium (which has a tendency to fly to the top of the atmosphere). It's kind of a shame we use a non-renewable resource to create balloons as decorations and toys for children, that only last a day or two.