But you are ignoring the security of cold storage, with liquid network it is possible with Lightning it is not.
In addition, the rates for large quantities are higher in Lightning Network.
Discussion
By building a reserve of course anything can be transferred instantly because it is just IOU. Why not build a robust gold reserve foundation and get back to gold standard? Liquid network doesn’t have to be bitcoin it can be anything. I see it as a more reliable reserve system. Bitcoin doesn’t need reserve.