Is it possible to tax the currency holders for maintaining Zcash ecosystem?

First, forgive my poor English.
A common problem for a POW system is how to insure the security after issuance is complete. If the trading volume is very large and the coin price is high enough in future, it is not a problem. The transaction fee would sustain the system. Otherwise the system would be in danger if no extra incentive implemented except transaction fees. One solution is inflation, that’s now happening in Monero. I don’t think it ‘s a good idea. Those turn to POS + inflation are even worse.
Another solution is to tax the holders and I think it’s reasonable. Let’s consider the traditional bank systems. It is reasonable for customers to get interests from banks for their deposits because the money is in inflation. The gap between interest and inflation sustain the bank system. But in a fix-amount cryptocurrency system, it is deflation. So, I think it is reasonable for holders to get a negative interest to sustain the minimum security requirement of the system.
What I talk about is not a ZIP, but it’s helpful to think about the sustainable problem earlier although Zcash is still inflation in next few years.