Say bitcoin was the single tax. Then people would just not use bitcoin. That's why it wouldn't make for an effective tax.
Land is always in demand (the economic term being that demand is inelastic) since everyone needs it, and it is the source of all material wealth (agriculture, energy, commodities). Thus it is an effective tax.
I have yet to hear an argument for an alternative to land that is more sensible to tax.
So either you need to say that LVT applies to those kinds of assets, or you need a different explanation for why land and not other assets.