> Storing hydrogen in general isn't very difficult.

That's not accurate, storing hydrogen is very difficult. The atoms are so small that they pass into the molecular matrix of storage containers, sometimes even when kept at extreme temperatures and pressures, causing "hydrogen embrittlement", which eventually destroys the container and releases all of the hydrogen.

The only truly reliable way to store hydrogen over appreciable time frames is when it's bound in molecular forms, like fossil fuels or ammonia.