Here's a dumb question. If there was just one tax, the lvt, what would stop businesses sort of rediscovering income tax.

I mean putting a line on your pay slip called "lvt contribution" and then state the pre-lvtc salary in job descriptions and stuff like that.

Similarly with vat and related taxes. The incentive in both cases being to signal: here's what we would pay/charge if it weren't for the government. Which is presumably the current incentive to state before tax salary/cost (this assumption could well be totally wrong).