Inflation is too uniform, I guess. Why not just take the $100 bill out of circulation?

Also, this seems to be falling into the classic fallacy that sovereign governments which control fiat currencies still levy taxes for revenue. Yes, it keeps things conventional and understandable to think that way, and yes, some forced circulation of currency via taxation is necessary to keep it alive, but broadly speaking, an entity like the U.S. Government does not need to collect tax revenue to function. The purpose of taxation at that level is to shape behavior and so effect policy outcomes via nudging. That still might justify a "high-denomination" bill tax, but let's not kid ourselves about "making up for lost revenue".